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Soureshjani OK, Massumi A, Nouri G. Sustainable colonization of Mars using shape optimized structures and in situ concrete. Sci Rep 2023; 13:15747. [PMID: 37735490 PMCID: PMC10514203 DOI: 10.1038/s41598-023-42971-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Accepted: 09/17/2023] [Indexed: 09/23/2023] Open
Abstract
The major obstacle to Martian colonization is the mission cost which requires significant reduction. From the structural engineering point of view, importing materials and structural elements from Earth or massive excavations on the surface of Mars require an enormous amount of energy; thus, inflatable and under-surface structures as the main options for Martian colonization seem unrealistically expensive. Construction of affordable buildings onsite using only in situ sources may represent an ideal solution for Martian colonization. On the other hand, solar energy, at the early stage of colonization, would be the only available, practical, and low-cost energy source on Mars. Though, for sustainable and broad colonization, the energy required for construction and the construction cost should be minimized. Here, we propose three types of simple (relatively optimized), perforated, and algorithmic shape-optimized Martian structures to minimize the material and energy required for construction as well as the construction cost using only in situ resources. These structural forms can be considered remarkable steps towards sustainable structural construction and colonization on Mars. Also, these innovative structures were designed to minimize the tensile stress (maximize the compressive stress) and enable the use of in situ concrete. Our data indicate that compared to our previous study, the material and energy required for construction as well as the construction cost can be reduced by more than 50%. Acceptance criteria and limitations appropriate to the Martian environment, and desirable structural and material behaviors were defined to evaluate whether or not the behavior of a structure under the applied loads and conditions will be acceptable. To detect potential issues for onsite construction and evaluate the geometry of the models, a 1:200 3D model of the best structural form was printed.
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Affiliation(s)
| | - Ali Massumi
- Department of Civil Engineering, Faculty of Engineering, Kharazmi University, Tehran, Iran.
| | - Gholamreza Nouri
- Department of Civil Engineering, Faculty of Engineering, Kharazmi University, Tehran, Iran
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Abstract
On Mars, structural loads and the low tensile strength of in-place Martian binders make existing solutions for Martian structures uneconomical because they are based on the terrestrial sources like inflatable units. Here we address this issue by introducing and analyzing three innovative structural forms in accordance with the structural engineering point of view using symmetric optimum parabolic rotated arch shapes and in-place waterless sulfur-based concrete. These forms minimize the tensile stresses under Martian structural loads. Probable Martian structural loads, including gravity, wind, marsquakes, asteroid and meteoroid impact loads and their effects have been investigated and calculated. The proposed models were analyzed under Martian structural loads using the implicit finite element method and the results were compared to two concrete structural forms from previous studies. The proposed models could tolerate Martian structural loads with complete elastic behavior and would significantly decrease the Martian colonization cost due to using Martian resources and reduce element importing from Earth.
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Affiliation(s)
- Omid Karimzade Soureshjani
- grid.412265.60000 0004 0406 5813Department of Civil Engineering, Faculty of Engineering, Kharazmi University, Tehran, Iran
| | - Ali Massumi
- grid.412265.60000 0004 0406 5813Department of Civil Engineering, Faculty of Engineering, Kharazmi University, Tehran, Iran
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Nazeri A, Ganapathy AV, Massumi A, Massumi M, Tuzun E, Stainback R, Segura AM, Elayda MA, Razavi M. Effect of botulinum toxin on inducibility and maintenance of atrial fibrillation in ovine myocardial tissue. Pacing Clin Electrophysiol 2017; 40:693-702. [PMID: 28345131 DOI: 10.1111/pace.13079] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Revised: 02/16/2017] [Accepted: 03/14/2017] [Indexed: 11/26/2022]
Abstract
BACKGROUND Aberrant vagal stimulation may promote the generation and propagation of atrial fibrillation (AF). Researchers have suggested that botulinum toxin (BTX), a neurotoxin that decreases neural vagal stimulation, may decrease the incidence of postoperative AF. The exact electrophysiologic mechanism underlying the observations and histopathologic alterations associated with BTX are unclear. OBJECTIVE To investigate the electrophysiologic, functional, and histopathologic effects of BTX on fibrillation induction in ovine atria. METHODS Eight sheep underwent BTX injections into their pulmonary veins, atrial fat pads, and ventricular walls. Electrophysiology with pacing was performed at baseline and 7 days after injection to evaluate the atrial effective refractory period (ERP) and vulnerability to AF with and without vagal stimulation. Echocardiography was performed at baseline and day 7. After euthanasia, histopathologic analysis was performed. RESULTS Seven sheep completed the study. For both atria, there was significant shortening in the ERP with vagal stimulation versus no stimulation on day 0 but not on day 7. More aggressive pacing was required to induce AF in the left atrium on day 7 than on day 0. Echocardiography on day 7 showed no significant changes in ejection fraction or new wall-motion abnormalities of the left and right ventricle. Histopathologic analysis showed no significant adverse effects. CONCLUSION The subacute BTX effect reduced the vulnerability of atrial tissue to AF induction and reduced the vagal influence on atrial ERP shortening compared to baseline levels. Direct BTX injection did not cause myocardial dysfunction or histologic adverse effects.
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Affiliation(s)
- Alireza Nazeri
- Department of Cardiology, Texas Heart Institute, Houston, Texas.,Department of Internal Medicine, Section of Cardiology, Baylor College of Medicine, Houston, Texas
| | - Anand V Ganapathy
- Department of Cardiology, Texas Heart Institute, Houston, Texas.,Department of Internal Medicine, Section of Cardiology, Baylor College of Medicine, Houston, Texas
| | - Ali Massumi
- Department of Cardiology, Texas Heart Institute, Houston, Texas
| | - Mehran Massumi
- Department of Cardiology, Texas Heart Institute, Houston, Texas.,Department of Internal Medicine, Section of Cardiology, Baylor College of Medicine, Houston, Texas
| | - Egemen Tuzun
- Cardiovascular Research Laboratories, Texas Heart Institute, Houston, Texas
| | | | - Ana-Maria Segura
- Department of Cardiovascular Pathology, Texas Heart Institute, Houston, Texas
| | - Macarthur A Elayda
- Department of Biostatistics and Epidemiology, Texas Heart Institute, Houston, Texas
| | - Mehdi Razavi
- Department of Cardiology, Texas Heart Institute, Houston, Texas.,Department of Internal Medicine, Section of Cardiology, Baylor College of Medicine, Houston, Texas
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Khalid U, Massumi A, Shaibani A. Swallowing-induced Supraventricular Tachyarrhythmia. Rev Cardiovasc Med 2017; 18:53-58. [DOI: 10.3909/ricm0863] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Nazeri A, Elayda MA, Segura AM, Stainback RF, Nathan J, Lee VV, Bove C, Sampaio L, Grace B, Massumi A, Razavi M. Comparative Efficacy of Nebivolol and Metoprolol to Prevent Tachycardia-Induced Cardiomyopathy in a Porcine Model. Tex Heart Inst J 2017; 43:477-481. [PMID: 28100964 DOI: 10.14503/thij-15-5495] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Chronic tachycardia is a well-known cause of nonischemic cardiomyopathy. We hypothesized that nebivolol, a β-blocker with nitric oxide activity, would be superior to a pure β-blocker in preventing tachycardia-induced cardiomyopathy in a porcine model. Fifteen healthy Yucatan pigs were randomly assigned to receive nebivolol, metoprolol, or placebo once a day. All pigs underwent dual-chamber pacemaker implantation. The medication was started the day after the pacemaker implantation. On day 7 after implantation, each pacemaker was set at atrioventricular pace (rate, 170 beats/min), and the pigs were observed for another 7 weeks. Transthoracic echocardiograms, serum catecholamine levels, and blood chemistry data were obtained at baseline and at the end of the study. At the end of week 8, the pigs were euthanized, and complete histopathologic studies were performed. All the pigs developed left ventricular cardiomyopathy but remained hemodynamically stable and survived to the end of the study. The mean left ventricular ejection fraction decreased from baseline by 34%, 20%, and 20% in the nebivolol, metoprolol, and placebo groups, respectively. These changes did not differ significantly among the 3 groups (P =0.51). Histopathologic analysis revealed mild left ventricular perivascular fibrosis with cardiomyocyte hypertrophy in 14 of the 15 pigs. Both nebivolol and metoprolol failed to prevent cardiomyopathy in our animal model of persistent tachycardia and a high catecholamine state.
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Sievert H, Rasekh A, Bartus K, Morelli RL, Fang Q, Kuropka J, Le D, Gafoor S, Heuer L, Safavi-Naeini P, Hue TF, Marcus GM, Badhwar N, Massumi A, Lee RJ. Left Atrial Appendage Ligation in Nonvalvular Atrial Fibrillation Patients at High Risk for Embolic Events With Ineligibility for Oral Anticoagulation. JACC Clin Electrophysiol 2015; 1:465-474. [DOI: 10.1016/j.jacep.2015.08.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 08/06/2015] [Accepted: 08/27/2015] [Indexed: 10/22/2022]
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Safavi-Naeini P, Razavi M, Saeed M, Rasekh A, Massumi A. A Review of the LARIAT Suture Delivery Device for Left Atrial Appendage Closure. J Tehran Heart Cent 2015; 10:69-73. [PMID: 26110004 PMCID: PMC4477089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 01/12/2015] [Indexed: 11/16/2022] Open
Abstract
The prevalence of atrial fibrillation (AF) is 1-2 % in the general population, and the risk of embolic stroke in AF patients is 4-5 times higher than that in the general population. AF-related strokes are often severe, and the rate of permanent disability is much higher among individuals who have AF-related strokes than in those who have strokes unrelated to AF. In patients with AF, more than 90 % of thrombi originate from the left atrial appendage (LAA). The purpose of this paper is to review the efficacy and safety of performing the LAA closure with the LARIAT Suture Delivery Device to prevent AF-related stroke in patients with contraindications to oral anticoagulant therapy.
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Affiliation(s)
| | | | | | - Abdi Rasekh
- Corresponding Author: Abdi Rasekh, 6624 Fannin Street, Suite 2480, Houston, TX 77030 USA. Tel: +1 713 5295530. Fax: +1 832 2018121.
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Safavi-Naeini P, Rasekh A, Razavi M, Saeed M, Massumi A. Sudden Cardiac Death in Coronary Artery Disease. Coron Artery Dis 2015. [DOI: 10.1007/978-1-4471-2828-1_24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Nazeri A, Constantine G, Rasekh A, Massumi A, Saeed M, Massumi M, Raz S, Razavi M. Contact-force rebound, but not its absolute value, may enable differentiation between steam pops with and without cardiac perforation. Eur Heart J 2013. [DOI: 10.1093/eurheartj/eht308.p2333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Massumi A, Chelu MG, Nazeri A, May SA, Afshar-Kharaghan H, Saeed M, Razavi M, Rasekh A. Initial experience with a novel percutaneous left atrial appendage exclusion device in patients with atrial fibrillation, increased stroke risk, and contraindications to anticoagulation. Am J Cardiol 2013; 111:869-73. [PMID: 23312129 DOI: 10.1016/j.amjcard.2012.11.061] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Revised: 11/29/2012] [Accepted: 11/29/2012] [Indexed: 12/30/2022]
Abstract
Atrial fibrillation (AF) increases by fivefold a patient's risk for thromboembolic stroke. The main source of emboli in AF is the left atrial appendage (LAA). Therefore, LAA closure could reduce the risk for thromboembolic events in AF. The investigators report the first United States experience with a novel percutaneous LAA closure device, the Lariat snare device, and its outcomes in 21 patients with AF, CHADS2 scores ≥2, and contraindications to anticoagulation. The LAA was closed with a snare containing suture from within the pericardial space. The intraoperative success of the procedure was confirmed by left atrial angiography and transesophageal echocardiographic color Doppler flow. The effectiveness of the procedure was evaluated by follow-up transesophageal echocardiography. The incidence of periprocedural and short-term complications was assessed by reviewing medical records. Twenty patients (100%) had successful LAA exclusion that was preserved at 96 ± 77 days. No patient had a stroke during an average of 352 ± 143 days of follow-up. One patient had right ventricular perforation and tamponade that required surgical exploration and repair. Two patients required prolonged hospitalization: 1 because of pericardial effusion that required repeat pericardiocentesis and 1 because of noncardiac co-morbidities. Three patients developed pericarditis <1 month after the procedure, of whom 1 had associated pericardial effusion that required drainage. In conclusion, percutaneous LAA exclusion can be achieved successfully and with an acceptable incidence of periprocedural and short-term complications. Further studies are needed to determine whether LAA exclusion lowers the long-term risk for thromboembolic events in patients with AF and contraindications to anticoagulation.
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Azpurua FE, Dougherty KG, Massumi A, Strickman NE. Fistula from right internal mammary artery to superior vena cava after use of a laser sheath to extract a pacemaker lead. Tex Heart Inst J 2012; 39:727-730. [PMID: 23109780 PMCID: PMC3461661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A 55-year-old woman presented with dyspnea on exertion due to a right internal mammary artery-to-superior vena cava arteriovenous fistula that occurred after pacemaker lead extraction with a laser sheath. The fistula was successfully repaired by placing a covered stent in the right internal mammary artery. In this unusual location, endovascular stenting is a reasonable alternative to coil embolization or surgical repair of an arteriovenous fistula resulting from laser lead extraction.
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Affiliation(s)
- Federico E Azpurua
- Department of Adult Cardiology, Texas Heart Institute at St. Luke's Episcopal Hospital, Houston, Texas 77030, USA
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Ganjehei L, Massumi A, Razavi M, Wilson JM. Orthostatic hypotension as a manifestation of vitamin B12 deficiency. Tex Heart Inst J 2012; 39:722-3. [PMID: 23109778 PMCID: PMC3461697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A 90-year-old woman with orthostatic hypotension and near-syncope was found to have a low-normal level of vitamin B(12) and no other medical findings that could explain her orthostasis. Her symptoms responded to vitamin B(12) replacement therapy. This case shows that vitamin B(12) deficiency can induce orthostatic hypotension and syncope that are correctable by vitamin B(12) replacement.
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Affiliation(s)
- Leila Ganjehei
- Department of Adult Cardiology, Texas Heart Institute at St. Luke's Episcopal Hospital, Houston, Texas 77030, USA
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Barekatain A, Rasekh A, Massumi A. Exclusion of the left atrial appendage to prevent stroke in cases of atrial fibrillation. Tex Heart Inst J 2012; 39:535-537. [PMID: 22949772 PMCID: PMC3423289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Affiliation(s)
- Armin Barekatain
- Department of Internal Medicine, The University of Texas Health Science Center at Houston, USA
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Ganjehei L, Barekatain A, Razavi M, Massumi A, Rasekh A. Biventricular intracardiac device implanted in a patient with persistent left superior vena cava. Tex Heart Inst J 2012; 39:586-587. [PMID: 22949787 PMCID: PMC3423296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Affiliation(s)
- Leila Ganjehei
- Department of Cardiology, Texas Heart Institute at St. Luke's Episcopal Hospital, Houston, Texas 77030, USA
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Ganjehei L, Nazeri A, Massumi A, Razavi M. Marked attenuation of shock burden by the use of antitachycardia pacing therapy in a patient with an implanted cardioverter-defibrillator. Tex Heart Inst J 2012; 39:568-570. [PMID: 22949781 PMCID: PMC3423292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A 76-year-old man was admitted to our institution for elective exchange of his implanted cardioverter-defibrillator generator. Nine years earlier, he had been diagnosed with nonischemic cardiomyopathy and nonsustainable ventricular tachycardia. At that time, he had received a single-chamber implanted cardioverter-defibrillator, which was upgraded to a dual-chamber implanted cardioverter-defibrillator 3 years later. In the course of the current admission, routine device interrogation during exchange of the patient's implanted cardioverter-defibrillator generator revealed 150 episodes of ventricular tachycardia in the preceding 7 months, 137 of which had been successfully treated by antitachycardia pacing therapy without shock. These findings show the remarkable effectiveness of antitachycardia pacing in terminating ventricular tachycardia while preventing the delivery of shocks, minimizing patient discomfort, and avoiding implanted cardioverter-defibrillator battery depletion.
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Affiliation(s)
- Leila Ganjehei
- Department of Adult Cardiology, Texas Heart Institute at St. Luke's Episcopal Hospital, Houston, Texas 77030, USA
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Ganjehei L, Razavi M, Massumi A. Cardiac resynchronization therapy: a decade of experience and the dilemma of nonresponders. Tex Heart Inst J 2011; 38:358-360. [PMID: 21841860 PMCID: PMC3147217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Affiliation(s)
- Leila Ganjehei
- Department of Cardiology, Texas Heart Institute at St. Luke's Episcopal Hospital, Houston, TX 77030, USA
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Ganjehei L, Massumi A, Razavi M, Rasekh A. Stroke prevention in nonvalvular atrial fibrillation. Tex Heart Inst J 2011; 38:350-352. [PMID: 21841857 PMCID: PMC3147190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Affiliation(s)
- Leila Ganjehei
- Department of Cardiology, Texas Heart Institute at St. Luke's Episcopal Hospital, Houston, TX 77030, USA
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Nazeri A, Elayda MA, Dragnev L, Frank CM, Qu J, Afonso VX, Rasekh A, Saeed M, Cheng J, Shuraih M, Massumi A, Razavi M. Heterogeneity of left ventricular signal characteristics in response to acute vagal stimulation during ventricular fibrillation in dogs. Tex Heart Inst J 2011; 38:621-626. [PMID: 22199421 PMCID: PMC3233327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Studies have shown that long-term vagal stimulation is protective against ventricular fibrillation; however, the effects of acute vagal stimulation during ventricular fibrillation in the normal heart have not been investigated. We examined the effects of acute vagal stimulation on ventricular fibrillation in a canine model. In 4 dogs, we induced 30-second periods of ventricular fibrillation by means of intraventricular pacing. During 2 of the 4 periods of fibrillation that we analyzed, vagal stimulation was delivered through electrodes in the caudal ends of the vagus nerves. Noncontact unipolar electrograms were recorded from 3 ventricular regions: the basal septum, apical septum, and lateral free wall. We then computed the most frequent cycle length, mean organization index, and mean electrogram amplitude for each region. During fibrillation, vagal stimulation shortened the most frequent cycle lengths in the basal septum (P=0.02) and apical septum (P=0.0001), but not in the lateral wall (P=0.46). In addition, vagal stimulation significantly reduced the mean organization indices in the apical septum (P <0.001) and lateral wall (P <0.001), but not in the basal septum (P=0.19). Furthermore, vagal stimulation raised the mean electrogram amplitude in the basal septum (P <0.01) but lowered it substantially in the apical septum (P=0.00005) and lateral wall (P=0.00003). We conclude that vagal stimulation acutely affects the characteristics of ventricular fibrillation in canine myocardium in a spatially heterogeneous manner. This nonuniformity of response may have implications with regard to manipulating the autonomic system as a means of modifying the substrate for ventricular dysrhythmias.
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Affiliation(s)
- Alireza Nazeri
- Division of Cardiology, Texas Heart Institute at St. Luke's Episcopal Hospital, Houston, Texas 77030, USA
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Ganjehei L, Massumi A, Nazeri A, Razavi M. Cardiac arrhythmias in women. Tex Heart Inst J 2011; 38:157-159. [PMID: 21494526 PMCID: PMC3066817] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Affiliation(s)
- Leila Ganjehei
- Department of Cardiology, Texas Heart Institute at St. Luke's Episcopal Hospital, Houston, Texas 77030, USA
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Eifling M, Razavi M, Massumi A. The evaluation and management of electrical storm. Tex Heart Inst J 2011; 38:111-121. [PMID: 21494516 PMCID: PMC3066819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Electrical storm is an increasingly common and life-threatening syndrome that is defined by 3 or more sustained episodes of ventricular tachycardia, ventricular fibrillation, or appropriate shocks from an implantable cardioverter-defibrillator within 24 hours. The clinical presentation can be dramatic. Electrical storm can manifest itself during acute myocardial infarction and in patients who have structural heart disease, an implantable cardioverter-defibrillator, or an inherited arrhythmic syndrome. The presence or absence of structural heart disease and the electrocardiographic morphology of the presenting arrhythmia can provide important diagnostic clues into the mechanism of electrical storm. Electrical storm typically has a poor outcome.The effective management of electrical storm requires an understanding of arrhythmia mechanisms, therapeutic options, device programming, and indications for radiofrequency catheter ablation. Initial management involves determining and correcting the underlying ischemia, electrolyte imbalances, or other causative factors. Amiodarone and β-blockers, especially propranolol, effectively resolve arrhythmias in most patients. Nonpharmacologic treatment, including radiofrequency ablation, can control electrical storm in drug-refractory patients. Patients who have implantable cardioverter-defibrillators can present with multiple shocks and may require drug therapy and device reprogramming. After the acute phase of electrical storm, the treatment focus should shift toward maximizing heart-failure therapy, performing revascularization, and preventing subsequent ventricular arrhythmias. Herein, we present an organized approach for effectively evaluating and managing electrical storm.
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Affiliation(s)
- Michael Eifling
- Department of Cardiology, Texas Heart Institute at St. Luke's Episcopal Hospital, Houston, Texas 77030, USA
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Ganjehei L, Massumi A, Nazeri A, Razavi M. Pharmacologic management of arrhythmias. Tex Heart Inst J 2011; 38:344-349. [PMID: 21841856 PMCID: PMC3147219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Affiliation(s)
- Leila Ganjehei
- Department of Cardiology, Texas Heart Institute at St. Luke's Episcopal Hospital, Houston, TX 77030, USA
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Bensler JM, Frank CM, Razavi M, Rasekh A, Saeed M, Haas PC, Nazeri A, Massumi A. Tachycardia-mediated cardiomyopathy and the permanent form of junctional reciprocating tachycardia. Tex Heart Inst J 2010; 37:695-698. [PMID: 21224950 PMCID: PMC3014141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Permanent junctional reciprocating tachycardia, or atrioventricular reentrant tachycardia utilizing a slowly conducting posteroseptal accessory pathway, is a rare form of reentrant supraventricular tachycardia in children and adults. The characteristic features of this narrow complex tachycardia are a long RP interval and inverted P waves in the inferior leads. This form of accessory-pathway-mediated tachycardia, which is usually incessant, can lead to a tachycardia-induced cardiomyopathy and congestive heart failure if left untreated. Radiofrequency ablation of the accessory pathway in permanent junctional reciprocating tachycardia is the definitive treatment in these patients, and in many instances the effects of prolonged tachycardia on ventricular function are reversible after successful ablation. We present an illustrative case.
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MESH Headings
- Adult
- Cardiomyopathies/diagnosis
- Cardiomyopathies/etiology
- Cardiomyopathies/physiopathology
- Cardiomyopathies/surgery
- Catheter Ablation
- Electrocardiography
- Electrophysiologic Techniques, Cardiac
- Female
- Heart Conduction System/physiopathology
- Heart Conduction System/surgery
- Humans
- Recovery of Function
- Stroke Volume
- Tachycardia, Atrioventricular Nodal Reentry/complications
- Tachycardia, Atrioventricular Nodal Reentry/diagnosis
- Tachycardia, Atrioventricular Nodal Reentry/physiopathology
- Tachycardia, Atrioventricular Nodal Reentry/surgery
- Tachycardia, Supraventricular/complications
- Tachycardia, Supraventricular/diagnosis
- Tachycardia, Supraventricular/physiopathology
- Tachycardia, Supraventricular/surgery
- Treatment Outcome
- Ventricular Function, Left
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Affiliation(s)
- James Michael Bensler
- Department of Cardiology, Texas Heart Institute at St. Luke's Episcopal Hospital, Houston, Texas 77030, USA.
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Nazeri A, Massumi A, Rasekh A, Saeed M, Frank C, Razavi M. Cardiac resynchronization therapy in patients with right ventricular pacing-induced cardiomyopathy. Pacing Clin Electrophysiol 2009; 33:37-40. [PMID: 19821931 DOI: 10.1111/j.1540-8159.2009.02594.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND It is not known whether patients with normal baseline left ventricular (LV) function who develop right ventricular (RV) pacing-induced cardiomyopathy as a result of dual-chamber pacing can benefit from cardiac resynchronization therapy (CRT). We retrospectively assessed the effect of a CRT upgrade on RV pacing-induced cardiomyopathy. METHODS AND RESULTS We reviewed the charts of patients who received a CRT device for RV pacing-induced cardiomyopathy. We assessed the effects of CRT on LV function, recovery, and other response parameters. From September 2005 through February 2009, 21 patients (13 men; aged 63 + or - 9 years) underwent a treatment upgrade to a CRT system. Before the dual-chamber pacemaker was implanted, the LV ejection fraction (LVEF) was 53 + or - 2.3%. After pacing, the LVEF was 31.2 + or - 3.8%, the LV end-diastolic dimension (LVEDD) was 5.8 + or - 0.5 cm, and B-type natriuretic peptide (BNP) levels were 426 + or - 149 pg/mL. The duration of pacing before documentation of pacing-induced cardiomyopathy was 3.8 + or - 1.5 months. All the patients had been on a stable medical regimen for at least 2 months. After the upgrade to CRT, the follow-up time was 4.9 + or - 0.9 months. Sixteen patients (76%) reported a significant improvement in their symptoms. After the CRT upgrade, the LVEF increased to 37.4 + or - 9.0% (P < 0.01 vs pre-CRT). The LVEDD decreased to 5.0 + or - 1.0 cm (P = 0.03 vs pre-CRT), and BNP levels decreased to 139 + or - 92 pg/mL (P = 0.08 vs pre-CRT). CONCLUSION A CRT upgrade is an effective treatment for RV pacing-induced cardiomyopathy and should be implemented as soon as the diagnosis is established. Unfortunately, about 24% of our patients did not respond to the upgrade.
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Affiliation(s)
- Alireza Nazeri
- Texas Heart Institute at St. Luke's Episcopal Hospital, Houston, Texas, USA
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Nazeri A, Massumi A, Wilson JM, Frank CM, Bensler M, Cheng J, Saeed M, Rasekh A, Razavi M. Arrhythmogenicity of weight-loss supplements marketed on the Internet. Heart Rhythm 2009; 6:658-62. [DOI: 10.1016/j.hrthm.2009.02.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2008] [Accepted: 02/10/2009] [Indexed: 10/21/2022]
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Frank CM, Razavi M, Saeed M, Bogaev RC, Massumi A. Recognition and management of complex rhythm disorders in heterotopic heart transplantation. J Heart Lung Transplant 2009; 28:294-6. [PMID: 19285624 DOI: 10.1016/j.healun.2008.12.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2008] [Revised: 11/12/2008] [Accepted: 12/01/2008] [Indexed: 11/18/2022] Open
Abstract
Managing arrhythmias is challenging in patients who have undergone heterotopic heart transplantation because of the superimposed rhythms of the native and donor hearts. We present the case of a 43-year-old man with a previously placed biventricular pacemaker who underwent heterotopic heart transplantation and later developed acute rejection of the donor heart, which led to bradycardia and pause-dependent ventricular fibrillation. The patient remained clinically stable in the short term, likely because of partial recovery of myocardial function in the native heart. He later underwent placement of a pacing lead in the donor heart, allowing linking of the two hearts via a biventricular pacemaker.
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Affiliation(s)
- Christopher M Frank
- Department of Transplant Research, Texas Heart Institute at St. Luke's Episcopal Hospital, Houston, Texas 77030, USA
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Nazeri A, Rasekh A, Massumi A, Razavi M. Coalescence of splines on a basket mapping catheter during ablation using a closed-loop irrigation catheter. Europace 2009; 11:258-9. [PMID: 19126657 DOI: 10.1093/europace/eun364] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Alireza Nazeri
- Department of Cardiology, Texas Heart Institute, Houston, TX 77030-2312, USA
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27
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Paisley RD, Arora HS, Nazeri A, Massumi A, Razavi M. Migraine and vasodepressor syncope in a large family. Tex Heart Inst J 2009; 36:468-469. [PMID: 19876431 PMCID: PMC2763453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We evaluated a 47-year-old woman for recurrent migraine and syncope. The patient had 7 children (not examined by the authors), all of whom also experienced migraine and syncope. The patient's father, now deceased, had reportedly experienced migraine and episodes of feeling faint. All 5 of the patient's siblings reported migraine, and 4 of the 5 reported syncope. The case of our patient, which we discuss herein, suggests a genetic link between these 2 conditions, both of which include vascular dysregulation in their pathogenesis. To our knowledge, the medical literature contains no previous description of familial associations of combined migraine and syncope.
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Affiliation(s)
- Robert D Paisley
- Department of Cardiology, Texas Heart Institute at St. Luke's Episcopal Hospital, and University of Texas Medical School at Houston, Houston, Texas 77030, USA
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Nazeri A, Massumi A, Rasekh A, Saeed M, Frank C, Wilson JM, Lopez JA, Razavi M. Cardiac resynchronization therapy may improve symptoms of congestive heart failure in patients without electrical or mechanical dyssynchrony. Europace 2008; 11:86-8. [PMID: 19056743 DOI: 10.1093/europace/eun326] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AIMS Cardiac resynchronization therapy (CRT) has reportedly not been effective in the absence of electrical or mechanical dyssynchrony. We present six patients with severe left ventricular (LV) dilation, mitral regurgitation (MR), and non-ischaemic cardiomyopathy who underwent CRT. We assessed the effects of CRT on LV ejection fraction (EF), LV dimensions, mitral valve regurgitant fraction (RF), pulmonary arterial pressures (PAP), and serum levels of B-natriuretic peptide (BNP). METHODS AND RESULTS All patients had severe LV dilation (>/=6.8 cm) and no electrical or mechanical dyssynchrony. All patients underwent CRT-D (with defibrillator) without complications. Average echocardiographic follow-up was 4.6 months. Mean LVEF increased significantly from 20.8 +/- 3.4 to 28.3 +/- 2.9% after CRT (P < 0.01). Mean LV end-diastolic dimension decreased significantly from 6.9 +/- 0.15 to 6.45 +/- 0.33 cm after CRT (P = 0.03); mean BNP serum level decreased from 1738 +/- 526 to 1040 +/- 768 pg/mL (P = 0.07). Baseline RF decreased from 45 +/- 12.2 to 20 +/- 10.9% after CRT-D (P = 0.009). Mean PAP decreased from 48.5 +/- 5.8 to 42.6 +/- 5.2 (P = 0.03). In five patients, New York Heart Association class symptoms improved by at least one level. No patients required assist devices or transplantation. One patient was hospitalized during follow-up. CONCLUSION We describe six patients with severe LV dilation without evidence of electrical or mechanical dyssynchrony who improved with CRT, possibly due to improvement in MR.
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Affiliation(s)
- Alireza Nazeri
- Department of Cardiology, Texas Heart Institute at St Luke's Episcopal Hospital, Houston, 6624 Fannin, Suite 2480, Houston, TX, USA
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Yap SK, Massumi A, Golden LH, Rhodes CT, Fung HL. Comparative Pharmacological Evaluation of Different Sublingual Nitroglycerin Formulations. ACTA ACUST UNITED AC 2008. [DOI: 10.3109/03639047609051902] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Kohsaka S, Razavi M, Massumi A. Idiopathic Ventricular Fibrillation Successfully Terminated by Radiofrequency Ablation of the Distal Purkinje Fibers. Pacing Clin Electro 2007; 30:701-4. [PMID: 17461880 DOI: 10.1111/j.1540-8159.2007.00731.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A 21-year-old woman was admitted for evaluation of recurrent episodes of syncope. She had several spontaneous and abrupt loss of consciousness episodes while at the emergency department, caused by sustained and nonsustained ventricular fibrillation episodes. Each episode was initiated by a certain premature ventricular complex, which remained the same in subsequent ventricular fibrillation episodes. She had a total of eight more episodes of ventricular fibrillation during her admission, despite administration of intravenous antiarrhythmic agents. A diagnosis of idiopathic ventricular fibrillation was made. Radiofrequency catheter ablation was performed, targeting the distal Purkinje system. Ventricular fibrillation was noninducible after the procedure, and the patient has been symptom-free for the past 1 year.
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Affiliation(s)
- Shun Kohsaka
- Department of Cardiology, Texas Heart Institute at St. Luke's Episcopal Hospital and Baylor College of Medicine, Houston, Texas, USA.
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31
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Kassaian SE, Alidoosti M, Saleh DK, Zeinali AMH, Salarifar M, Sahraian AM, Shirani S, Kazazi EH, Darvish S, Marzban M, Abbasi SH, Massumi A. Risk factors for major complications due to delay in surgery in staged carotid stenting and coronary bypass graft surgery. EUROINTERVENTION 2007; 3:60-66. [PMID: 19737686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
AIMS To answer the question whether the delay in coronary artery bypass grafting (CABG) after carotid stenting (CAS) results in adverse events, we describe our experience with planned staged CAS followed by CABG. METHODS AND RESULTS We retrospectively surveyed our hospital carotid stenting data base, to identify all patients who were scheduled to undergo staged carotid stenting followed by CABG. A total of 39 patients who underwent CAS were candidates for staged CABG but only 28 (71.7%) of them referred. In the interval between carotid stenting and CABG, 4 deaths occurred (14.2% of cases), all of them were in the first week after CAS and due to cardiac problems. Also, 2 patients (7.1%) had a minor stroke. Increased number of predictors of type C (most important was stenosis of 95%-99%), age > 75 or significant valvular heart disease were associated with increased rate of complications after CAS. CONCLUSION Should carotid intervention be performed in the high risk group of patients with > 4 suggested predictors of type C (most importantly is stenosis of 95%-99%), valvular heart disease or age > 75, physicians should closely observe the patients (perhaps in the hospital) during the waiting period before CABG, particularly in the first week after carotid stenting.
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Affiliation(s)
- Seyed Ebrahim Kassaian
- Interventional Cardiologist, Tehran Heart Center, Medical Sciences, University of Tehran, Tehran, Iran
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Levin V, Nemeth M, Colombowala I, Massumi A, Rasekh A, Cheng J, Coles JA, Ujhelyi MR, Razavi M. Interatrial Conduction Measured During Biventricular Pacemaker Implantation Accurately Predicts Optimal Paced Atrioventricular Intervals. J Cardiovasc Electrophysiol 2007; 18:290-5. [PMID: 17313655 DOI: 10.1111/j.1540-8167.2006.00744.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Optimizing atrioventricular (AV) delay during biventricular (BiV) pacemaker implantation can require substantial resources. Hence, a simpler method is desirable. We hypothesized that interatrial conduction time (IACT), measured at the time of BiV device implant, could be a surrogate value for the optimal AV delay. OBJECTIVE This study determined the relationship between paced IACT and the optimal paced AV delay (PAV), as determined by echocardiography. METHODS Consecutive subjects (N = 25; age = 66 +/- 10 years; M/F: 17/8) undergoing BiV pacemaker implantation and in sinus rhythm were included. Cannulation of the coronary sinus (CS) was at the operator's discretion. A quadripolar electrophysiology catheter was inserted via the guiding sheath into the inferiolateral CS to measure left atrial depolarization. The IACT was calculated as the interval between right atrial stimulation artifact and earliest deflection on the coronary sinus catheter electrogram. Subsequently, during atrial pacing the PAV was determined using transmitral pulsed wave Doppler echocardiography (iterative method). The relationship between paced IACT and PAV was then determined. RESULTS The mean +/- SD paced IACT and PAV were 126 +/- 25 msec and 157 +/- 23 msec, respectively. There was a strong positive correlation between the paced IACT and PAV (r = 0.73, P < 0.001). The equation describing the relationship was PAV = 0.68 * (IACT + 104) msec. CONCLUSIONS The paced IACT has a strong correlation with the echo derived optimal PAV. This method may be used to program PAV intervals without need for echocardiography in patients undergoing BiV pacemaker implantation.
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Affiliation(s)
- Vadim Levin
- Lehigh Valley Hospital, Allentown, Pennsylvania, USA
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33
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Nader A, Massumi A, Cheng J, Razavi M. Inherited arrhythmic disorders: long QT and Brugada syndromes. Tex Heart Inst J 2007; 34:67-75. [PMID: 17420796 PMCID: PMC1847921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Inherited arrhythmic disorders comprise a group of syndromes with unique genetic abnormalities and presentations but with very similar clinical outcomes and complications, the most terrifying of which are life-threatening arrhythmias and sudden cardiac death. Advances in molecular biology have enabled us to define and pinpoint many such disorders, which were previously labeled as idiopathic, to specific genes on various chromosomes. The current trend in the management of these potentially deadly disorders is to use pharmacotherapy (antiarrhythmic agents) and defibrillators for the prevention of sudden death; however, targeted therapy at a molecular level appears to be the path of the future. Herein, we review long QT and Brugada syndromes and focus on the genetics, pathophysiology, and clinical manifestations of these inherited arrhythmogenic disorders that affect patients with structurally normal hearts.
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Affiliation(s)
- Amirali Nader
- Department of Cardiac Electrophysiology, Texas Heart Institute at St. Luke's Episcopal Hospital, Houston, Texas 77030, USA
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34
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Razavi M, Cheng J, Rasekh A, Yang D, Delapasse S, Ai T, Meade T, Donsky A, Goodman MJ, Massumi A. Slow Pathway Ablation Decreases Vulnerability to Pacing-Induced Atrial Fibrillation: Possible Role of Vagal Denervation. Pacing Clin Electro 2006; 29:1234-9. [PMID: 17100676 DOI: 10.1111/j.1540-8159.2006.00528.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
BACKGROUND Studies indicate that success of radiofrequency (RF) ablation of atrial fibrillation (AF) may be in part due to vagal denervation. RFAof supraventricular tachycardia (SVT) has been associated with vagal denervation. The effects of slow pathway (SP) ablation on AF inducibility have not been studied. OBJECTIVE To test the hypothesis that SP ablation renders AF less inducible. METHODS Consecutive patients referred for SVT were studied. After atrioventricular nodal reentrant tachycardia (AVNRT) was confirmed they underwent induction of AF. After SP ablation AF induction was reattempted. Vulnerability to AF was reassessed. RESULTS Twenty-four patients were enrolled; eight were not inducible for AF in the preablative state. Mean CLof the AVNRT was 340 +/- 16 ms. The average RF ablation time was 131 +/- 42 seconds. Presence of junctional rhythm was required. Of the 16 with inducible AF two patients had AF induced during routine invasive electrophysiology study. None of these had inducible AF after SP ablation. Fourteen of 16 patients required specific AF induction. Ten of these were noninducible after SP ablation; two were inducible after SP ablation but with a more aggressive pacing protocol (P < 0.03 compared to preablation) and two had no change in AF vulnerability. Seven of the eight noninducible patients remained noninducible for AF post SP ablation. In the 12 patients who were inducible prior but noninducible after ablation the mean atrial effective refractory period (AERP) increased for both BCL at 400 and 600 ms (400/216 +/- 8 ms preablation vs 400/248 +/- 12 ms postablation, P < 0.03; 600/228 +/- 8 ms preablation vs 600/259 +/- 6 ms postablation, P < 0.04). There were no significant changes in AERP of patients who remained inducible or who were noninducible before ablation. The average ablation time for patients who became noninducible after ablation was significantly higher than those who had no change in inducibility or remained inducible but at a more aggressive pacing threshold (157 +/- 24 seconds vs 35 +/- 5 seconds; P < 0.005). CONCLUSION SP ablation acutely decreases vulnerability to pacing-induced AF in patients with AVNRT. This may reflect the effect of ablation on atrial vagal tone.
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Affiliation(s)
- Mehdi Razavi
- Texas Heart Institute/St. Luke's Episcopal Hospital, Houston, Texas 77030, USA.
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35
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Friedman PA, McClelland RL, Bamlet WR, Acosta H, Kessler D, Munger TM, Kavesh NG, Wood M, Daoud E, Massumi A, Schuger C, Shorofsky S, Wilkoff B, Glikson M. Dual-Chamber Versus Single-Chamber Detection Enhancements for Implantable Defibrillator Rhythm Diagnosis. Circulation 2006; 113:2871-9. [PMID: 16769912 DOI: 10.1161/circulationaha.105.594531] [Citation(s) in RCA: 210] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Delivery of inappropriate shocks caused by misdetection of supraventricular tachycardia (SVT) remains a substantial complication of implanted cardioverter/defibrillator (ICD) therapy. Whether use of optimally programmed dual-chamber ICDs lowers this risk compared with that in single-chamber ICDs is not clear. METHODS AND RESULTS Subjects with a clinical indication for ICD (n=400) at 27 participating centers received dual-chamber ICDs and were randomly assigned to strictly defined optimal single- or dual-chamber detection in a single-blind manner. Programming minimized ventricular pacing. The primary end point was the proportion of SVT episodes inappropriately detected from the time of programming until crossover or end of study. On a per-episode basis, 42% of the episodes in the single-chamber arm and 69% of the episodes in the dual-chamber arm were due to SVT. Mortality (3.5% in both groups) and early study withdrawal (14% single-chamber, 11% dual-chamber) were similar in both groups. The rate of inappropriate detection of SVT was 39.5% in the single-chamber detection arm compared with 30.9% in the dual-chamber arm. The odds of inappropriate detection were decreased by almost half with the use of the dual-chamber detection enhancements (odds ratio, 0.53; 95% confidence interval, 0.30 to 0.94; P=0.03). CONCLUSIONS Dual-chamber ICDs, programmed to optimize detection enhancements and to minimize ventricular pacing, significantly decrease inappropriate detection.
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MESH Headings
- Aged
- Arrhythmias, Cardiac/diagnosis
- Arrhythmias, Cardiac/physiopathology
- Arrhythmias, Cardiac/therapy
- Atrioventricular Node/physiology
- Cardiac Pacing, Artificial/methods
- Confidence Intervals
- Cross-Over Studies
- Defibrillators, Implantable/adverse effects
- Defibrillators, Implantable/standards
- Diagnosis, Differential
- Electric Countershock/instrumentation
- Electric Countershock/methods
- Electrocardiography
- Electrophysiologic Techniques, Cardiac/methods
- Equipment Design
- Equipment Failure
- Female
- Heart Rate/physiology
- Humans
- Male
- Middle Aged
- Sensitivity and Specificity
- Single-Blind Method
- Tachycardia, Supraventricular/diagnosis
- Tachycardia, Supraventricular/physiopathology
- Tachycardia, Supraventricular/therapy
- Tachycardia, Ventricular/diagnosis
- Tachycardia, Ventricular/physiopathology
- Tachycardia, Ventricular/therapy
- Time Factors
- Ventricular Fibrillation/diagnosis
- Ventricular Fibrillation/physiopathology
- Ventricular Fibrillation/therapy
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Affiliation(s)
- Paul A Friedman
- Division of Cardiovascular Diseases, Mayo Clinic, 200 First St SW, Rochester, Minnesota 55905, USA
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Friedman PA, Acosta H, Kessler D, Munger TM, Kavesh NG, Wood M, Daoud E, Massumi A, Schuger C, Shorofsky S, Wilkoff B, Glikson M. Detection of SVT with dual chamber versus single chamber detection enhancements (The DETECT SVT trial). Heart Rhythm 2005. [DOI: 10.1016/j.hrthm.2005.08.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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37
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Jefferies JL, Younis GA, Flamm SD, Rasekh A, Massumi A. Chest pain and diaphragmatic pacing after pacemaker implantation. Tex Heart Inst J 2005; 32:106-7. [PMID: 15902837 PMCID: PMC555839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Affiliation(s)
- John L Jefferies
- Department of Cardiology, Texas Heart Institute at St. Luke's Episcopal Hospital, MC 1-133, P.O. Box 20345, Houston, TX 77225-0345, USA.
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38
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Acosta H, Massumi A, Malik R, Ahmad S, Antonio C, Syed ZA. AutoCapture with Dual-Coil Leads of Implantable Cardioverter Defibrillator. Pacing Clin Electrophysiol 2005; 28 Suppl 1:S267-9. [PMID: 15683512 DOI: 10.1111/j.1540-8159.2005.00100.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AutoCapture (AC) can confirm ventricular capture with true bipolar single coil leads of implantable cardioverter defibrillators (ICD). The compatibility of AC with a new, true bipolar, dual-coil ICD lead needed to be evaluated. This multicenter study enrolled 46 patients (69 +/- 10 years, 37 men) undergoing ICD implantation. All patients received a true bipolar, dual-coil lead. Evoked response (ER) sensitivity and AC threshold tests were performed using a pulse generator with the AC algorithm. Mean capture threshold was 0.85 +/- 0.67 V, pacing impedance 612 +/- 225 Omega, R wave amplitude 13.85 +/- 6.17 mV, and defibrillation threshold 14.4 +/- 5.1 J. AC was recommended in 45 patients (97.8%) with ER and polarization values of 14.86 +/- 7.32 mV and 0.87 +/- 0.69 mV, respectively. The AC algorithm was highly compatible with true bipolar, dual-coil ICD leads. An AC algorithm specifically designed for an ICD may improve the generator longevity. Further examination of AC compatibility with other leads is warranted.
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Affiliation(s)
- Helbert Acosta
- Trinity Medical Center, Rock Island, Illinois 61201, USA.
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39
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Villareal RP, Lee VV, Elayda M, Wilson JM, Massumi A. Reply. J Am Coll Cardiol 2004. [DOI: 10.1016/j.jacc.2004.09.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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40
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Villareal RP, Hariharan R, Liu BC, Kar B, Lee VV, Elayda M, Lopez JA, Rasekh A, Wilson JM, Massumi A. Postoperative atrial fibrillation and mortality after coronary artery bypass surgery. J Am Coll Cardiol 2004; 43:742-8. [PMID: 14998610 DOI: 10.1016/j.jacc.2003.11.023] [Citation(s) in RCA: 452] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2002] [Revised: 10/25/2002] [Accepted: 11/13/2003] [Indexed: 02/06/2023]
Abstract
OBJECTIVES We sought to determine if the occurrence of postoperative atrial fibrillation (AF) affects early or late mortality following coronary artery bypass surgery (CABG). BACKGROUND Atrial fibrillation is the most common arrhythmia seen following CABG. METHODS The Texas Heart Institute Cardiovascular Research Database was used to identify all patients that developed AF after isolated initial CABG from January 1993 to December 1999 (n = 994). This population was compared with patients who underwent CABG during the same period but did not develop AF (n = 5,481). In-hospital end points were adjusted using logistic regression models to account for baseline differences. Long-term survival was evaluated using a retrospective cohort design, where Cox proportional hazards methods were used to adjust for baseline differences, and with case-matched populations (n = 390, 195 per arm). RESULTS Atrial fibrillation was diagnosed in 16% of the population. Postoperative AF was associated with greater in-hospital mortality (odds ratio [OR] 1.7, p = 0.0001), more strokes (OR 2.02, p = 0.001), prolonged hospital stays (14 vs. 10 days, p < 0.0001), and a reduced incidence of myocardial infarction (OR 0.62, p = 0.01). At four to five years, survival was worse in patients who developed postoperative AF (74% vs. 87%, p < 0.0001 in the retrospective cohort; 80% vs. 93%, p = 0.003 in the case-matched population). On multivariate analysis, postoperative AF was an independent predictor of long-term mortality (adjusted OR 1.5, p < 0.001 in the retrospective cohort; OR 3.4, p = 0.0018 in the case-matched population). CONCLUSIONS The occurrence of AF following CABG identifies a subset of patients who have a reduced survival probability following CABG. The impact of various strategies, such as antiarrhythmics and warfarin, aimed at reducing AF and its complications deserves further study.
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Affiliation(s)
- Rollo P Villareal
- Section of Cardiology, Self Regional Healthcare, Greenwood, South Carolina 29646, USA.
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41
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Jefferies JL, Moreira W, Massumi A, Stainback RF. Images in cardiovascular medicine. Rapid progression of extreme septal hypertrophic cardiomyopathy. Circulation 2003; 108:e136. [PMID: 14609999 DOI: 10.1161/01.cir.0000093663.63794.47] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- John L Jefferies
- Department of Cardiology, St Luke's Episcopal Hospital, Texas Heart Institute, Houston, Tex 77030, USA
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Marenco JP, Greenfield RA, Massumi A, Syed ZA, Mcintyre T, Hardage M, Link MS, Homoud MK, Estes M, Wang PJ. Use of the AutoCapture Pacing System with implantable defibrillator leads. Pacing Clin Electrophysiol 2003; 26:471-3. [PMID: 12687870 DOI: 10.1046/j.1460-9592.2003.00074.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
INTRODUCTION Previous studies using various bipolar pacemaker leads have shown that the AutoCapture (AC) Pacing System is able to verify ventricular capture and regulate pacing output, increasing patient safety with respect to unexpected threshold changes and potentially prolonging device longevity. An increasing number of patients with implantable cardioverter defibrillators (ICDs) require ventricular pacing that contributes to a shortening of longevity of these systems. This prospective study tested the compatibility of the AC system with bipolar ICD leads. METHODS The AC algorithm was evaluated prior to ICD testing in 30 ICD recipients. A single coil, active fixation, true bipolar ventricular lead was implanted in 21 patients, and a dual coil, passive fixation, integrated bipolar ventricular lead was implanted in 9 patients. A ventricular evoked response sensitivity test and an AC threshold test were performed using a pacemaker with the ventricular AC algorithm. RESULTS AC was recommended in 22/30 (73.3%) of implants, including 20/21 (95.2%) with the single coil and 2/9 (22.2%) with the dual coil lead. Mean polarization was lower (1.23 +/- 0.95 mV vs 3.70 +/- 2.33 mV, P = 0.013) while the mean evoked response was higher (18.04 +/- 8.29 mV vs 10.13 +/- 4.22 mV, P = 0.002) with the single coil leads. CONCLUSION Automatic threshold tracking using the AC is compatible with ICD leads. Leads with lower polarization and greater evoked response are more likely to result in recommendation of AC use. Use of this system offers the potential for increasing ICD generator longevity and improving patient safety in response to late unexpected threshold increases.
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Liu BC, Villareal RP, Hariharan R, Rasekh A, Massumi A. Inappropriate shock delivery and biventricular pacing cardiac defibrillators. Tex Heart Inst J 2003; 30:45-9. [PMID: 12638671 PMCID: PMC152836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
In the United States, physicians adapt currently available defibrillators to accommodate leads for biventricular pacing in those congestive heart failure patients who might benefit from cardiac resynchronization and who are additionally at risk for sudden cardiac death. The adaptation of the lead system of available defibrillators to also allow them to function as biventricular pacemakers presents occasions in which inappropriate shocks are delivered due to double counting of the right and left ventricular depolarizations by the implantable cardiac defibrillator. We reviewed a series of inappropriate shock deliveries that occurred after the implantation of biventricular pacing cardiac defibrillators at our institution; all of these shocks were related to ventricular double counting. Each had different underlying causes and management strategies. Complications such as these emphasize the importance of attentiveness to ventricular channel electrograms and to device sensing with the use of biventricular pacing cardiac defibrillators. In addition, a thorough working knowledge of pacemaker and defibrillator operation is essential for the prediction and correction of inappropriate therapies.
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Affiliation(s)
- Brant C Liu
- The Department of Cardiology and Electrophysiology, Texas Heart Institute and St Luke's Episcopal Hospital, Houston, Texas 77030, USA.
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Gupta K, Villareal RP, Rasekh A, Massumi A. Pacemaker lead entrapment syndrome. Tex Heart Inst J 2003; 30:84-5. [PMID: 12638682 PMCID: PMC152847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Affiliation(s)
- Kamal Gupta
- Department of Cardiology, Texas Heart Institute and St. Luke's Episcopal Hospital, and Baylor College of Medicine, Houston, Texas 77030, USA
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Massumi A, Najafi N, Barzegari H. Speciation of Cr(VI)/Cr(III) in environmental waters by fluorimetric method using central composite, full and fractional factorial design. Microchem J 2002. [DOI: 10.1016/s0026-265x(01)00163-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Croitoru M, Muthupillai R, Seger JJ, Massumi A, Lopez A, Flamm S. Cardiac cine magnetic resonance imaging identifies anatomical and functional abnormalities in patients with arrhythmias of right ventricular origin. J Am Coll Cardiol 2002. [DOI: 10.1016/s0735-1097(02)81657-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Abstract
The autonomic nervous system plays a major role in affecting the cardiac milieu and promoting malignant ventricular activity. The measurement of heart rate variability (HRV) is a noninvasive tool for assessing the status of the autonomic nervous system. A depressed HRV among post-myocardial infarction patients is a well-established risk factor for arrhythmic death. A reduced HRV has also been used to identify diabetic patients with autonomic neuropathy. This paper presents recent developments in the use of HRV, focusing on further refinement and validation of the use of both linear and nonlinear dynamics for sudden death prognostication, evaluation of the effect of specific pharmacologic agents on HRV, and assessment of HRV in health and in specific disease states that have been associated with an increased mortality risk.
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Affiliation(s)
- Rollo P Villareal
- Center for Cardiac Arrhythmias and Electrophysiology, St. Luke's Episcopal Hospital/Texas Heart Institute, 6720 Bertner, MC 1-133, Houston, TX 77030, USA.
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Gamssari F, Mahmood H, Ho JS, Villareal RP, Liu B, Rasekh A, Garcia E, Massumi A. Rapid ventricular tachycardias associated with cilostazol use. Tex Heart Inst J 2002; 29:140-2. [PMID: 12075874 PMCID: PMC116744] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
A 92-year-old woman with normal systolic function had recently begun using the newly approved phosphodiesterase III inhibitor cilostazol when she was admitted with lower-extremity pain. Cilostazol is indicated for patients with intermittent claudication and contraindicated for patients with congestive heart failure. Two days after admission, the patient developed ventricular tachycardia. Cilostazol was discontinued, and shortly thereafter the ventricular tachycardia subsided. In this case, cilostazol was apparently an important predisposing factor for ventricular tachycardia.
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Affiliation(s)
- Farhad Gamssari
- Texas Heart Institute at St. Luke's Episcopal Hospital, Houston 77030, USA
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Wilson JM, Villareal RP, Hariharan R, Massumi A, Muthupillai R, Flamm SD. Magnetic resonance imaging of myocardial fibrosis in hypertrophic cardiomyopathy. Tex Heart Inst J 2002; 29:176-80. [PMID: 12224720 PMCID: PMC124756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Abstract
Myocardial fibrosis can occur in patients who have hypertrophic cardiomyopathy in the absence of epicardial coronary disease. In such patients, myocardial fibrosis has been linked to a poorer prognosis than in those without fibrosis. Gadolinium-DTPA delayed-enhancement magnetic resonance imaging (de-MRI) accurately identifies regions of myocardial fibrosis. We used de-MRI to screen for myocardial fibrosis in 8 patients with nonobstructive hypertrophic cardiomyopathy that had been diagnosed by 2-dimensional echocardiography. After localization of the heart and acquisition of electrocardiographically gated cine images, gadolinium-DTPA (0.2 mmol/kg) was administered to the patient. Fifteen minutes later, de-MRI images were obtained using a T1-weighted, inversion-recovery fast, low-angle shot sequence. Images were gated to end-diastole and obtained during a single breath-hold. The inversion time was modified iteratively to obtain maximal nulling of the signal from the ventricular myocardium. Regions of myocardium with abnormally high signals (>300% of remote normal myocardium) were designated as fibrotic. Eight patients with hypertrophic cardiomyopathy underwent de-MRI. The mean age was 52 years, the mean left ventricular mass was 201 grams, and the mean ejection fraction was 0.68. In the 6 patients with recent clinical deterioration, de-MRI showed clearly delineated areas of myocardial fibrosis; no such areas were seen in the 2 asymptomatic patients. We conclude that patients with symptomatic hypertrophic cardiomyopathy display regions of abnormal signal intensity on de-MRI that likely represent fibrosis. This technique may provide useful information in the evaluation of such patients and warrants further study.
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Affiliation(s)
- James M Wilson
- Department of Radiology/Cardiovascular Magnetic Resonance Imaging, St Luke's Episcopal Hospital and Texas Heart Institute, Houston, USA
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Villareal RP, Woodruff AL, Massumi A. Gender and cardiac arrhythmias. Tex Heart Inst J 2001; 28:265-75. [PMID: 11777151 PMCID: PMC101202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
The incidence of certain clinical arrhythmias varies between and women. Clinical and experimental observations suggest the existence of true differences in electrophysiologic properties between the sexes. We review these differences, possible mechanisms, clinical implications, and therapeutic considerations in the treatment of various arrhythmias in women.
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Affiliation(s)
- R P Villareal
- Department of Cardiology, Clinical Cardiac Electrophysiology, Texas Heart Institute and St Luke's Episcopal Hospital, Houston 77030, USA
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