DNA barcoding of pear psyllids (Hemiptera: Psylloidea: Psyllidae), a tale of continued misidentifications

Pear psyllids (Hemiptera: Psylloidea: Psyllidae: Cacopsylla spp.) belong to the most serious pests of pear (Pyrus spp.). They damage pear trees by excessive removal of phloem sap, by soiling the fruits with honeydew which, in turn, provides a substrate for sooty mould, and by transmission of Candidatus Phytoplasma spp., the causal agents of the pear decline disease. The morphological similarity, the presence of seasonal dimorphism that affects adult colour, size and wing morphology and uncritical use of species names, led to much confusion in the taxonomy of pear psyllids. As a result, pear psyllids have been frequently misidentified. Many of the entries attributed to Cacopsylla pyricola and other species in the GenBank are misidentifications which led to additional, unnecessary confusion. Here we analysed DNA barcodes of 11 pear psyllid species from eastern Asia, Europe and Iran using four mitochondrial gene fragments (COI 658 bp, COI 403 bp, COI-tRNAleu-COII 580 bp and 16S rDNA 452 bp). The efficiency of identification was notably high and considerable barcoding gaps were observed in all markers. Our results confirm the synonymies of the seasonal forms of Cacopsylla jukyungi ( = C. cinereosignata, winter form) and C. maculatili ( = C. qiuzili, summer form) previously suggested based on morphology. Some previous misidentifications (C. chinensis from China, Japan and Korea = misidentification of C. jukyungi; C. pyricola and C. pyrisuga from East Asia = misidentification of C. jukyungi and C. burckhardti, respectively; C. pyricola from Iran = misidentification of C. bidens, C. pyri and Cacopsylla sp.) are also corrected. There is no evidence for the presence of European pear psyllid species in East Asia.

[Long-term outcome after endovascular treatment of high-risk patients with recurrently symptomatic intracranial stenoses of the posterior circulation]

PURPOSE

We present long-term clinical and duplex data from high-risk patients with severe, recurrent symptomatic stenoses of the vertebrobasilar circulation. We hypothesized that despite the greater risk of periprocedural complications in this patient group, interventional treatment would reduce the risk of recurrent strokes relative to the expected natural risk. We also predicted that the long-term treatment outcome would be positively influenced by the use of stents and by the periprocedural technical success rate.

MATERIALS AND METHODS

An analysis of our patient data base yielded 45 cases of stenosis of the vertebrobasilar circulation treated endovascularly in 42 patients between 1998 and 2006. Clinical and vascular diagnostic tests, both periinterventionally and during follow-up, were performed independently by experienced neurologists.

RESULTS

The technical success rate was 93%. Stents were used in 67% of the procedures. After 30 days, 24% of the patients showed post-procedural clinical deterioration. After an average period of 26.3 months, 17.8 % of the patients had deteriorated. 11.1% of the patients suffered severe permanent damage as a result of the procedure (mRs 3 - 6). Restenosis was found in 9.5% of the cases. There were no instances of a recurrent stroke during follow-up.

CONCLUSION

For this population of high-risk patients with recurrently symptomatic intracranial stenoses of the vertebrobasilar axis, endovascular treatment reduced the risk of stroke and death relative to the expected natural risk. The use of stents had no significant effect on the long-term results.

Afrotropical members of the jumping plant-louse genus Diclidophlebia (Hemiptera:Psylloidea)

African members of the pantropical genus Diclidophlebia Crawford (Paurocephalinae) are revised. Sixteen species are recognised including three known species, seven new species and six species that are not formally described owing to insufficient material. Adult and last larval instars are diagnosed and illustrated and keys are provided for identification. Five species are associated with Sterculiaceae (Malvales) and one each with Tiliaceae (Malvales), Irvingiaceae/Simaroubaceae (Rutales), Chrysobalanaceae (Rosales) and Euphorbiaceae (Euphorbiales). Host plants of other species are unknown. Possibly monophyletic groups include four species restricted to the Guineo-Congolian region and five species in the Sudano-Zambezian region.

Combined corrections for attenuation, depth-dependent blur, and motion in cardiac SPECT: a multicenter trial

BACKGROUND

The diagnostic accuracy of cardiac single photon emission computed tomography (SPECT) is limited by image-degrading factors, such as heart or subject motion, depth-dependent blurring caused by the collimator, and photon scatter and attenuation. We developed correction approaches for motion, depth-dependent blur, and attenuation and performed a multicenter validation.

METHODS AND RESULTS

Motion was corrected both transversely and axially with a cross-correlation technique. Depth-dependent blurring was corrected by first back-projecting each projection and then applying a depth-dependent Wiener filter row by row. Attenuation was corrected with an iterative, nonuniform Chang algorithm, based on a transmission scan-generated attenuation map. We validated these approaches in 112 subjects, including 36 women (20 healthy volunteers, 8 angiographically normal patients, and 8 patients with coronary artery disease [CAD] found by means of angiography) and 76 men (23 healthy volunteers, 10 angiographically normal patients, and 43 patients with CAD found by means of angiography). Either technetium 99m or thallium 201 was used for emission; either gadolinium 153 or Tc-99m was used for transmission. Images were reconstructed and blindly interpreted with a 5-point scale for receiver operating characteristic analysis in 2 ways: motion correction plus a Butterworth filter, and combined motion and blur and attenuation corrections. The interpretation by means of consensus was for the overall presence of CAD and vascular territory. The receiver operating characteristic curves for overall presence and each of the 3 main coronary arteries were all shifted upward and to the left and had larger areas under the curve, for combined corrections compared with motion correction and Butterworth. Sensitivity/specificity for motion correction and Butterworth were 84/69, 64/71, 32/94, and 71/81 overall for the left anterior descending, the right coronary artery, and circumflex territories, respectively, compared with 88/92, 77/93, 50/97, and 74/95, respectively, for the combined corrections.

CONCLUSIONS

The proposed combined corrections for motion, depth-dependent blur, and attenuation significantly improve diagnostic accuracy, when compared with motion correction alone.

[Incidence of thromboembolism after heart valve replacement: modifying factors]

The most important factors influencing thromboembolic rates after valve replacement are: 1) Cardiogenic factors such as left ventricular function, left atrial size and atrial rhythm. 2) Prosthesis-related factors such as type of prosthesis, position of prosthesis, and time after implantation. 3) Patient-related factors such as quality of anticoagulation and gender. 4) Conditions with hypercoagulability.

[Survived sudden cardiac death in aortic stenosis and Wolff-Parkinson-White syndrome: Differential diagnosis and therapy]

Based on a case of a 72 year old woman with hemodynamically non-significant aortic stenosis. WPW-syndrome and out-of-hospital cardiac arrest, the diagnostic assessment and differential diagnosis of potentially fatal arrhythmias are discussed. In particular, the incidence of supraventricular and ventricular arrhythmias in patients with WPW-syndrome, their prognostic impact and therapeutic options are outlined.

[Cerebral ischemic events: when and how to look for a cardiac embolism source?]

In industrialized countries, cerebral ischemic events rank third among the most frequent causes of death. In survivors, long-term disability may result. The diagnosis and therapy of preventable causes is therefore a major task. Echocardiography has proven to be most helpful in the search for cardioembolic sources, and the transesophageal approach (TEE) is superior to the transthoracic (TTE) in this specific indication. In patients in whom a cardioembolic source can be identified by clinical examination, 12-lead surface ECG or chest X-ray, an additional echocardiographic examination is not necessary. Patients under 50 with cerebral ischemic events should undergo TEE. In patients over 70 with a contraindication for long-term anticoagulant therapy, TEE has no therapeutic consequences and should therefore not be performed. In patients aged between 50 and 70 the diagnostic procedure of choice must be considered in each individual patient. It should be kept in mind that a more aggressive approach using TEE, from which therapeutic conclusions are drawn, has not clearly been shown to improve the prognosis of patients with cerebral ischemic events.

Benefits and limitations of rate adaptive pacing under laboratory and daily life conditions in patients with minute ventilation single chamber pacemakers

Rate adaptive pacing has been shown to improve hemodynamic performance and exercise tolerance during acute testing. However, there remain concerns about its benefit in daily life and possible complications incurred by unnecessary pacing. This double-blind crossover study compared the benefit of rate adaptive (SSIR) versus fixed rate (SSI) pacing under laboratory and daily life conditions in 20 rate incompetent patients with minute ventilation single chamber pacemakers (META II). The heart rate (HR) response during three different exercise tests (treadmill, bicycle ergometry, walking test) was correlated with the Holter findings during daily life in either pacing mode. The maximal HR was significantly higher in the SSIR-mode compared to the SSI-mode, both during laboratory testing (treadmill: 123 +/- 15 vs 93 +/- 29 beats/min; ergometry: 118 +/- 15 vs 89 +/- 27 beats/min; walking test: 127 +/- 9 vs 95 +/- 26 beats/min, all P values < 0.01) as well as during daily life (Holter: 126 +/- 13 vs 103 +/- 24 beats/min, P < 0.01). On Holter, the average HR (71 +/- 14 vs 71 +/- 8 beats/min) and the percentage of paced rhythm (54% vs 62%, SSI- vs SSIR-mode, P = NS) were not different in either mode. However, despite a 30% rate gain in the SSIR-mode, the exercise capacity remained unchanged, and only 38% of patients preferred the SSIR-mode. Minute ventilation pacemakers provide a physiological rate response to exercise. Irrespective of the protocol used, the findings of laboratory testing are comparable to those during daily life. However, patient selection for rate adaptive single chamber pacing should be made with caution, since the objective benefit of restoring normal chronotropy may subjectively be negligible for most patients.

[Recommendations for prevention of thromboembolism in heart valve diseases. Working Group on Valvular Heart Disease, European Society of Cardiology]

Thromboembolic events are still a major cause of morbidity and mortality in patients with native valvular heart disease and in patients with prosthetic heart valves. Although the introduction of oral anticoagulation reduced this risk, thromboembolism and anticoagulation-related hemorrhages still represent significant problems in the management of these patients. In this article the guidelines developed by the Working Group on Valvular Heart Disease of the European Society of Cardiology for the management of antithrombotic therapy in heart valve disease are thoroughly discussed. The indication for and intensity of anticoagulation in various clinical situations, the concept of risk factor-adjusted intensity of anticoagulation, and the concept of control of oral anticoagulation with the International Normalized Ratio are presented.

Antibiotic prophylaxis for infective endocarditis from an international group of experts towards a European consensus. Group of Experts of the International Society for Chemotherapy

Antibiotic prophylaxis for infective endocarditis is recommended for cardiac patients at risk who undergo an at-risk procedure. Efforts should focus on patients with the highest risk, i.e., those with a prosthetic valve undergoing a dental procedure. Amoxicillin is the main recommendation in patients who are not allergic to penicillin. In patients allergic to penicillin clindamycin orally or vancomycin intravenously are proposed. Aminoglycosides are added for gastrointestinal or urological procedures.

[Transesophageal echocardiography in the diagnosis of endocarditis]

Transesophageal echocardiography is a new diagnostic method for visualization of retrocardial structures and heart valves with high resolution. This retrospective analysis describes the use of and the findings by transesophageal echocardiography in patients suspected to suffer from endocarditis studied in three hospitals. 50 patients were studied; the diagnosis was confirmed in 64%, whereas 36% (controls) had other findings. The leading initial symptoms were fever and valvular incompetence. Laboratory parameters were altered in both groups with equal frequency. One or more diagnostic features were detected by transesophageal echocardiography in 88% of patients with endocarditis: vegetations (approximately with equal frequency on the mitral and the aortic, rarely on the tricuspid valve) were detected in 75% and/or abscesses in 22% of them. Only one patient in the control group with a history of endocarditis had vegetation-like structures on the aortic valve. Transesophageal echocardiography was on the average performed on the seventh day of hospitalization. With the exception of one female patient, all had been treated with antibiotics. Valve replacement was recommended in 65% of the patients with endocarditis and was in 59% also performed (single or double valve replacement), most frequently because of aortic or mitral regurgitation. The other patients were treated with antibiotics. Transesophageal echocardiography thus detects vegetations and abscesses in endocarditis frequently, findings that influence treatment in a significant manner.

High intensity transcranial Doppler signals (hits) after prosthetic valve implantation

High intensity transcranial Doppler signals (HITS), assumed to be caused by microemboli, have been reported to occur in many patients with mechanical heart valve prostheses. The aim of our study was to quantify these phenomena and to find possible differences. Furthermore, parameters which might influence the prevalence of HITS were investigated. Monitoring of both middle cerebral artery frequency shift spectra was carried out for 10 minutes in 100 patients having an aortic (n = 64) and (n = 5)/or (n = 31) mitral mechanical heart valve prosthesis. The spectra were off-line screened for HITS by ear. The findings were correlated with the degree of anticoagulation and with the time period since implantation. To examine if platelet aggregates would be the underlying cause, another HITS count was done for 10 minutes prior to and 40 minutes after i.v. injection of 250 mg aspirin (ASA) as well as after four days of 100 mg/day ASA orally in a group of seven patients. Prior to surgery, HITS were present in only one patient. Postoperatively, HITS were detected in 54 of 100 patients. There was no significant difference between left and right sides, no correlation with anticoagulation, and only a borderline correlation with the time interval since implantation. Sixty-six percent of the 50 patients monitored within the first three postoperative weeks had HITS as compared to only 42% in 50 subjects who were examined three months or later after surgery (p < 0.05). With regard to the number of HITS an inverse behaviour was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

[Transesophageal echocardiography: indications and findings. Experiences from 3 centers]

The introduction of transoesophageal echocardiography has greatly enhanced the noninvasive diagnostic possibilities in cardiology. This multicentre report analyses the findings in different indications as well as the rate of complications in 335 consecutive patients on whom transoesophageal echocardiography was performed. The most frequent indication was the search for a cardiac source of embolism (36%). Compared to patients with other indications, thrombi in the left atrial appendage, atrial septal aneurysms and protruding aortic atheromas were significantly more frequent in this group. Transoesophageal echocardiography was performed in 20% for the diagnosis of suspected endocarditis and vegetations and/or paravalvular abscesses could be demonstrated in 46% of these patients. Other important indications included the assessment of mitral valve disease, congenital heart disease, valve prosthesis dysfunction and aortic dissection. Clinically relevant complications occurred in 1.8% and were spontaneously reversible in all cases. Transoesophageal echocardiography is an extremely valuable and safe diagnostic tool in cardiology.

Diminished vascular response to inhibition of endothelium-derived nitric oxide and enhanced vasoconstriction to exogenously administered endothelin-1 in clinically healthy smokers

BACKGROUND

Smoking is a major risk factor for the development of atherosclerosis. Because endothelial dysfunction may be a marker for future atherosclerosis, we investigated the effects of smoking on endothelium-dependent control of vascular tone.

METHODS AND RESULTS

The effects of brachial arterial infusions of NG-monomethyl-L-arginine (L-NMMA), a nitric oxide synthesis inhibitor; sodium nitroprusside; endothelin-1; and norepinephrine on forearm blood flow (strain-gauge plethysmography) were compared in 29 long-term smokers and 16 nonsmokers. The acute effects of smoking on systemic hemodynamics, plasma catecholamines, and forearm vascular responses to these compounds were investigated in smokers only. Smokers did not differ from nonsmokers (n = 16) regarding the vascular effects of sodium nitroprusside (n = 13) or vasoconstriction due to norepinephrine and endothelin-1 (n = 16). Low-dose endothelin-1-induced vasodilation, believed to reflect endothelial prostacyclin or nitric oxide release, was absent in smokers (n = 16), and their increase of forearm vascular resistance (FVR) after L-NMMA (n = 13) was impaired (35.6 +/- 27.9% versus 118.8 +/- 43.2%, P < .001). Short-term smoking (n = 11) increased blood pressure, heart rate, and plasma epinephrine concentrations (P < .05 or less); enhanced endothelin-1-induced vasoconstriction (delta FVR, 457 +/- 192% versus 254 +/- 143%, P < .01); and decreased norepinephrine-induced vasoconstriction (P < .05), but had no effect on the other interventions.

CONCLUSIONS

Long-term smoking is associated with a diminished nitric oxide-dependent component of basal vascular tone and an impaired endothelium-dependent vasodilator response to low-dose endothelin-1 and short-term smoking enhances endothelin-1-induced vasoconstriction. Impaired endothelial control of vascular tone might reflect impairment of normal antiatherosclerotic endothelial functions in smokers, but the relevance of smoking-induced enhancement of endothelin-1 vasoconstriction remains to be determined.

Aortic valve replacement in elderly patients with aortic stenosis

OBJECTIVE

To assess the risk of aortic valve replacement and long-term follow-up in elderly patients with dominant aortic stenosis.

DESIGN

Retrospective analysis of patients who had aortic valve replacement over a 10 year period and were routinely seen in an outpatient clinic.

SETTING

University hospital.

PATIENTS

93 patients aged > or = 60 and 47 patients > or = 70 years with symptomatic aortic stenosis undergoing aortic valve replacement.

MAIN OUTCOME MEASURES

Early and late mortality in different age groups. Influence of preoperative signs and symptoms on overall outcome.

RESULTS

The proportion of patients older than 70 years increased from 11% in 1978 to 54% in 1986. Perioperative mortality was 3.6% and mortality after 2 and 5 years was 9% and 13% respectively. Survival was similar (85% and 83%, respectively) in patients aged 60-69 years (group 1, n = 93, mean age 64.5 (2.7) and patients aged > or = 70 years (group 2, n = 47, mean age 72.6 (2.5)). Additional coronary artery disease and coronary bypass grafting did not significantly affect survival. The cardiothoracic ratio was inversely related to survival (Cox regression, p < 0.05). Preoperative symptoms (syncope, angina pectoris, and dyspnoea) were similar in both patient groups. After a mean (SD) follow up of 51 (33) months 96% of surviving patients were in NYHA functional class I or II with no difference between the two age groups. Similarly, the cardiothoracic ratio and Sokolow index decreased to near normal values in both age groups.

CONCLUSION

The risk of aortic valve replacement in patients with dominant aortic stenosis is low and not significantly influenced by age. Therefore replacement may be performed without increased risk in elderly patients and with a good long-term outcome.

[Subjective tolerance to transesophageal echocardiography]

Transesophageal echocardiography (TEE) is a new semi-invasive diagnostic tool in cardiology. We studied tolerance of TEE. 95 out of 121 consecutive patients were interviewed using a detailed, structured questionnaire (42 questions). Most patients (97%) received midazolam prior to TEE. TEE was tolerated well by 89% (n = 84) of the patients. Patients receiving a higher dose of midazolam (> 0.04 mg/kg bodyweight) tolerated TEE better than those in the lower-dose group (p < 0.0005), but they experienced side effects more often (p < 0.05) and did not tolerate fatigue as well (p < 0.0005). TEE was tolerated less well by younger patients (age < or = 45 years); they experienced more often local irritation than older patients due to the endoscope (52% versus 20% in older patients, p < 0.005) and complained more often about dysphagia (70% versus 24%) and sore throat (60% versus 19%) (p < 0.0005) after TEE. Patients < or = 45 years reported more side effects by midazolam than older patients, such as palpitations (30% versus 2%), hiccups (17% versus 0%), poor concentration (20% versus 3%), nausea (13% versus 2%), ataxia (17% versus 3%) or fatigue (88% versus 59%) (p < 0.05 to 0.0005). Females were more often afraid of TEE (53%) and the endoscope (56%) than males (35% and 23%, p < 0.08 and p < 0.002) and also disliked the endoscope more often (42%) than men (19%, p < 0.03). Some women complained about headaches after TEE (10%), whereas men did not (p < 0.05). Thus, TEE, after premedication with midazolam, is subjectively well tolerated.(ABSTRACT TRUNCATED AT 250 WORDS)

The Omnicarbon tilting-disc heart valve prosthesis. A clinical and Doppler echocardiographic follow-up

From 1986 to 1990, 172 patients with a median age of 60.5 years (range 20 to 79 years) received 187 Omnicarbon valves (109 aortic valve replacements, 48 mitral valve replacements, and 15 double valve replacements). Patients were followed-up for a median observation period of 2.5 years (range 4 months to 5.2 years) by clinical and Doppler echocardiographic examination. Follow-up was complete in 98%. Operative mortality (death within 30 days) was 1.7%, and linearized late mortality was 2.6% per patient-year, corresponding to an actuarial survival rate for operative survivors of 89% after 4 years. The overall 4-year postoperative survival was 87% (93% for aortic valve replacement, 77% for mitral valve replacement). Compared with age- and sex-adjusted Swiss death rates, there was an excess mortality of 5% after 4 years. Percentages for freedom from valve-related complications at 4 years are as follows: thromboembolism, 98% (aortic valve replacement, 98%, and mitral valve replacement, 96%); anticoagulant-related hemorrhage, 95%; valve endocarditis, 96%; reoperation, 96%; and permanent valve-related impairment, 99%. The overall 4-year event-free survival was 76% (80% for aortic valve replacement and 69% for mitral valve replacement). New York Heart Association class improved in 88% of the patients by 1 to 3 grades, and only 3% remained in class III after operation. For the most commonly used aortic valve (23 mm), Doppler echocardiography revealed a peak pressure gradient of 29 +/- 10 mm Hg, a fractional shortening/peak pressure gradient ratio of 1.34 +/- 0.61, and a performance index of 0.35 +/- 0.08. In the most commonly used mitral valve (27 mm), the mean pressure gradient was 4.0 +/- 2.1 mm Hg. We conclude that excellent clinical and hemodynamic results can be obtained with the Omnicarbon prosthesis, in both the aortic and mitral positions.

Progression of aortic stenosis. Role of age and concomitant coronary artery disease

To determine the spontaneous progression of valvular aortic stenosis and to delineate clinical factors related to progression, a longitudinal study, including 49 patients (aged 16 to 81 years), was performed. All patients had auscultatory findings of aortic stenosis and multiple Doppler echocardiograms separated by at least 11 months. Rapid progression of aortic stenosis was defined as an increase of maximal instantaneous pressure gradient by > or = 10 mm Hg per year. During a mean follow-up period of 32 months (11 to 66 months), maximal pressure gradient rose from 38 +/- 15 to 60 +/- 20 mm Hg in the entire study population, resulting in a median increase of 7.2 mm Hg per year. In 21 patients (43 percent), an increase of > or = 10 mm Hg per year was found; in this subgroup with rapid progression, patients were older (64 vs 53 years, p < 0.01) and coronary artery disease was more prevalent (38 percent vs 7 percent, p = 0.01). We conclude that nearly half the patients with initially mild to moderate valvular aortic stenosis reveal a progression of > or = 10 mm Hg per year.

[Long-term effect of amiodarone therapy following myocardial infarct in patients with complex ventricular arrhythmias]

In the BASIS study, an improvement in 1 year survival of patients with asymptomatic complex ventricular arrhythmias with low-dose amiodarone was shown in comparison with an untreated control group. To assess whether this beneficial effect would last for a longer follow-up despite discontinuation of amiodarone therapy after one year, we assessed long-term survival and mode of death in the 91 survivors of the first year in the amiodarone treatment group and the 99 survivors in the control group by phone calls to private physicians, patients and hospitals. During a median follow-up of 72 (55-125) months, 184/193 patients (95%) could be reached. Causes of death during the follow-up were sudden (6 vs 14), non-sudden cardiac (8 vs 9), non cardiac (5 vs 9) and unknown (7 vs 6) in patients initially treated with amiodarone versus the control group respectively. The probability of death after 84 months was 30% in the amiodarone group and 45% in the control group, and was significantly lower in amiodarone treated patients with respect to all deaths (p = 0.024) as well as cardiac deaths (p = 0.027). This mortality reduction was only due to amiodarone treatment during the first year after the index infarction, whereas the survival curves did not differ significantly during the late follow-up. Thus, the risk of cardiac death is low after the first year after myocardial infarction and may not justify continued antiarrhythmic therapy in patients with initially complex asymptomatic ventricular arrhythmias.

Optimal timing of surgery for chronic mitral or aortic regurgitation

Symptoms tend to develop late in the course of both chronic mitral and chronic aortic regurgitation, and when the regurgitation is stable patients may enjoy many years of full activity free from disability. In the absence of complicating atrial fibrillation or coronary artery disease the onset of dyspnoe and fatigue usually indicate myocardial failure and possibly a lost opportunity for a low risk operation and long term benefit. Valve replacement for aortic regurgitation is a good operation which reduces left ventricular work. However, mitral valve replacement is unphysiologic and not surprisingly, the operative mortality and long term results are worse with an excess of deaths caused by left ventricular failure. While the need for operation is obvious when patients already have symptoms or when valvar regurgitation is increasing, timing is far more difficult for patients with severe, chronic, stable regurgitation who still enjoy a high quality of life. It is even more difficult in mitral regurgitation because the stakes are higher with a higher operative risk, but suitability for mitral valve reconstruction justifies earlier operation and therefore makes it mandatory for cardiologists to identify such patients.

Long-term benefit of 1-year amiodarone treatment for persistent complex ventricular arrhythmias after myocardial infarction

BACKGROUND

In the Basel Antiarrhythmic Study of Infarct Survival trial, low-dose amiodarone improved 1-year survival in patients with asymptomatic complex ventricular arrhythmias persisting 2 weeks after myocardial infarction. To assess whether this beneficial effect persisted despite discontinuation of amiodarone after 1 year, the long-term outcomes of all patients of the amiodarone-treated group (initially n = 98) and those of the control group (n = 114) were assessed.

METHODS AND RESULTS

After a mean follow-up of 72 (55-125) months, information on 96% of patients (203 of 212) was obtained regarding survival or cause of death. The probability of death after 84 months according to actuarial life-table analysis (Kaplan-Meier) was 30% for the amiodarone-treated patients and 45% for control patients. For the total follow-up, mortality remained significantly lower in the amiodarone group versus the control group regarding all deaths (p = 0.03) as well as cardiac death (p = 0.047). This mortality reduction was entirely due to the first-year amiodarone effect, since there was no significant mortality difference between groups when considering survival after discontinuation of amiodarone only.

CONCLUSIONS

These data suggest that the beneficial effect of amiodarone on survival in this high-risk group of patients persists for several years. In addition, the results stress the importance of early treatment after myocardial infarction, whereas the rate of sudden death and all cardiac death is low (1.6% and 4.1% per year, respectively) during late follow-up and therefore may not warrant further therapy.

Silent myocardial ischemia in glaucoma patients

The pathophysiological mechanism involved in normal-tension glaucoma is still not fully understood. Besides intraocular pressure, vascular and rheological factors have been described. In the present study, the prevalence of silent myocardial ischemia in patients of the same age with normal-tension glaucoma, primary open-angle glaucoma and cataract was compared. Our findings indicate that in all three groups ischemic episodes occurred more frequently than described in normal people. The most striking observation, however, was the fact that in normal-tension glaucoma the frequency was twice that of the other two groups.

[Ischemic cerebrovascular seizure: when and how should one search for a cardiac embolism source?]

Cerebral embolism originating from the heart accounts for approximately 15 to 20% of ischemic strokes. By far the most important source for cardiac embolism is associated with atrial fibrillation; in these patients immediate anticoagulation with no further echocardiographic diagnostic is recommended. The majority of the remaining cardiac sources of embolism--they originate from the left ventricle and the valves--can be suggested by clinical signs. In these cases a documentation by echocardiography is indicated. In contrast, embolism originating from the left atrium is rare and commonly not detectable by simple clinical means. The semi-invasive transesophageal echocardiography is able to visualize atrial pathologies with a high accuracy, but this investigation should be performed routinely only in patients less than 45 years old with no evidence for cardiac disease.

[Heart valve substitution: the effect of preoperative findings on long-term outcome]

BACKGROUND

In a retrospective analysis of 653 consecutive patients who underwent heart valve replacement by one single type of mechanical prosthesis (St. Jude Medical) at three Swiss university medical centers (Basel, Bern, Lausanne), the outcome was judged on the basis of preoperative variables. These variables should facilitate the timing of heart valve replacement.

METHODS

Preoperative evaluation includes NYHA classification of symptoms, chest X-ray, ECG, and LVEF on angiography. Postoperative outcome was assessed clinically at yearly intervals by NYHA classification, documentation of complications and mortality.

RESULTS

Five-year-survival rates were 96 and 88%, and complication-free rates were 82 and 76% respectively in patients after isolated aortic and mitral valve replacement. An unsatisfactory outcome with death or persistent severe symptoms was more frequent when preoperative symptoms at rest and atrial fibrillation were present.

CONCLUSION

Heart valve replacement should not be postponed until severe symptoms and functional impairment occur. Clinical criteria are at least as important for the timing of operation as the findings of more complex investigations.

[Transesophageal echocardiography: technique, indications and findings]

The introduction of transesophageal echocardiography (TEE) as a 'semi-invasive' technique with few complications in clinical practice represents a major diagnostic advance in the evaluation of cardiac disease. The close anatomic vicinity of the transducer to the heart and thoracic aorta allows the use of high frequency devices with better resolution compared to transthoracic echocardiography. Furthermore, the diagnostic gain when evaluating structures that are poorly visualized by the transthoracic approach such as the left atrial appendage, interatrial septum, prosthetic valves and the thoracic aorta is highly improved by TEE. Major indications for TEE include the search for a cardiac source of embolism and cardiac tumors, the work-up prior to balloon mitral valvuloplasty, the evaluation of prosthetic valves and the search for vegetations and aortic dissection. After a short summary of patient preparation, instrumentation and examination technique, the major indications, contraindications and complications are reviewed on the basis of our own experience and the literature.

Influence of different pressure gradients on late clinical outcome after aortic valve replacement

Late outcome vs. hemodynamic parameters were assessed and compared in a series of 44 patients followed for 10-17 years after aortic valve replacement either with a Starr-Edwards A 1260 (SE) or a Bjork-Shiley 60 degrees (BS) prosthesis. The two groups, 22 patients each, were selected by computer from the data base SG as to be matched for age, sex, underlying lesion, date of implantation, valve size, left ventricular function, and concomitant coronary artery disease. There was no significant difference in mortality and complication rates. Clinical evaluation at a mean of 12.5 +/- 2.2 years postoperatively revealed identical findings of heart size on chest X-rays (CTR 0.50 +/- 0.04 SE vs. 0.50 +/- 0.05 BS) and nearly identical incidence of left ventricular hypertrophy on the ECG (2/22 SE and 1/22 BS). There was a statistically significant difference in Doppler ultrasonic peak pressure gradients between the two valve types (SE 32 +/- 15 mmHg, BS 23 +/- 9 mmHg; p = 0.047), and of fractional shortening on M-mode echocardiograms (SE 30 +/- 9%, BS 37 +/- 8%, p = 0.038), but this was not reflected by a difference in the symptomatic status of the two groups. It is concluded, that in two groups of patients surviving 10-17 years after isolated aortic valve replacement with SE or BS valves, the statistically significant nine mmHg difference in gradient across the two valve types had no effect on long-term clinical outcome.

[Drug prevention and therapy of ventricular tachycardia]

Antiarrhythmic drugs of type I to IV (Vaughan Williams) are generally used for the treatment of ventricular tachycardia, especially in patients with symptomatic and hemodynamically not tolerated arrhythmias; however, randomized controlled studies revealed a beneficial effect on sudden cardiac death only for type-II (beta-blocking agents) and type-III (Amiodarone) antiarrhythmic drugs. These drugs are, therefore, the antiarrhythmic agents of first choice; but, in addition, underlying heart disease, triggering factors and heart-rate dependency should be considered.

Spectrum of subclinical and overt hypothyroidism: effect on thyrotropin, prolactin, and thyroid reserve, and metabolic impact on peripheral target tissues

PURPOSE

Subclinical hypothyroidism is found in about 7.5% of females and in about 3% of males. It appears to be a risk factor for atherosclerosis and for coronary heart disease and can affect various other target organs. The morbidity and clinical significance of subclinical hypothyroidism are controversial. Therefore, we evaluated the metabolic impact of progressive thyroid failure in patients with various degrees of hypothyroidism compared with control subjects.

PATIENTS AND METHODS

We investigated 86 female patients with the whole spectrum of subclinical hypothyroidism (n = 69) and of overt hypothyroidism (n = 17) and 52 euthyroid women as controls. All subjects underwent full medical and endocrine evaluations (including measurements of thyrotropin [TSH], TSH beta- and alpha-subunits, and prolactin before and after oral administration of thyrotropin-releasing hormone [TRH]) as well as lipid profiles and different tests of peripheral thyroid hormone action. All hypothyroid patients were divided into five categories according to disease severity: grades I to III (subclinical hypothyroidism, with normal thyroxine [T4] levels) and grades IV and V (overt hypothyroidism, with diminished T4).

RESULTS

In grade I subclinical hypothyroidism (basal TSH below 6 mU/L), we found significant changes in the clinical index (p less than 0.05), apoprotein A-I level (p less than 0.05), and stimulated prolactin level after oral TRH (p less than 0.001). The findings were similar in grade II (TSH 6 to 12 mU/L). Further changes could be demonstrated in grade III (TSH above 12 mU/L) with a definite elevation of ankle reflex time (p less than 0.001), serum myoglobin level (p less than 0.01), and, to a lesser extent, creatine kinase (p greater than 0.1). The mean low-density lipoprotein cholesterol (LDL-C) level showed an increase of 18%, which was not significant because of marked individual variations (p = 0.15). The frequency of elevated LDL-C levels was definitely higher in patients with grade III disease compared with the controls (42.9% versus 11.4%, p less than 0.05) and with patients with grades I and II disease. Total cholesterol, triglycerides, apoprotein B, and the systolic time intervals (pre-ejection period, corrected for heart rate [PEPc]) were clearly elevated only in overt hypothyroidism (grades IV and V) (p less than 0.01).

CONCLUSION

Subclinical hypothyroidism has significant effects on some peripheral target organs at an early stage (grades I and II), but affects LDL-C, skeletal muscle, and myocardial contractility only at a later stage (grades III, IV, and V). Our data of elevated LDL-C in grade III subclinical hypothyroidism provide a likely pathophysiologic explanation for the reported association of coronary heart disease with this syndrome. The impact of increased prolactin secretion, observed in subclinical hypothyroidism, on gonadal function and infertility has yet to be clarified. Therapy with thyroxine should be recommended in at least some patients with subclinical hypothyroidism. Patients with high TSH levels (above 12 mU/L) will require treatment because of the metabolic effects on several target organs. Before treatment is advocated in all patients with subclinical hypothyroidism, the benefits and long-term side effects of thyroid hormone therapy should be clarified by prospective studies in larger groups of patients.

Beneficial effect of amiodarone on cardiac mortality in patients with asymptomatic complex ventricular arrhythmias after acute myocardial infarction and preserved but not impaired left ventricular function

To determine whether the beneficial effect of low-dose amiodarone on survival in patients with complex ventricular arrhythmias after myocardial infarction was dependent on left ventricular (LV) function, results of the Basel Antiarrhythmic Study of Infarct Survival were analyzed. Two hundred twelve patients after acute myocardial infarction with asymptomatic complex arrhythmias were randomly assigned to receive amiodarone 200 mg/day or to a control group and followed up for 1 year. Results of mortality and arrhythmic events were related to baseline radionuclide LV ejection fraction. With preserved (greater than or equal to 40%) LV ejection fraction, there was a significantly lower 1-year cardiac mortality in patients treated with amiodarone (1 of 68 or 1.5%) versus control subjects (5 of 56 or 8.9%; p less than 0.03). This was not the case for patients with LV ejection fraction less than 40%. Similarly, arrhythmic events were significantly reduced only in patients with preserved LV function. These results suggest an interaction between the effects of amiodarone on survival and LV dysfunction in patients after acute myocardial infarction. Because of 2 other small studies with similar results, this finding may be of clinical relevance and should be addressed in ongoing and future research with this drug.

Doppler sonographic evaluation of mechanical and bioprosthetic mitral valve prostheses during exercise with a rate corrected pressure half time

OBJECTIVE

To compare the effect of exercise on pressure half time in patients with mechanical or bioprosthetic mitral valves. A relative pressure half time (pressure half time as a percentage of RR interval) was used in an attempt to correct for the shortening of the diastolic time interval caused by the increase in heart rate during exercise and thus to uncover the effects of valve design on pressure half time during exercise.

PATIENTS

Twenty clinically stable (New York Heart Association grade I-II) patients with mechanical (n = 12) or bioprosthetic (n = 8) mitral valves (median age 51) years. The median time since valve replacement was 42 months.

METHODS

Continuous wave Doppler echocardiography from the apical view at rest and during moderate supine bicycle exercise (50 W).

RESULTS

During exercise the mean (SD) heart rate increased from 79 (12) to 101 (12) beats per minute (95% confidence interval (95% CI) of difference, 15 to 29/min) and the peak pressure gradient from 11 (5) to 18 (6) mm Hg (95% CI of difference 5 to 9 mm Hg). The pressure half time decreased from 114 (30) to 78 (26) ms (95% CI of difference (30-42 ms). There was no difference between the valve types. The relative pressure half time remained unchanged in patients with mechanical valves during exercise (13 (4) rest and 13 (5)% exercise, respectively) and decreased in patients with bioprostheses (17 (3) and 12 (3)%, respectively (95% CI of difference 2 to 8%, p = 0.025).

CONCLUSIONS

In patients with mechanical mitral valves the decrease in the pressure half time during exercise is probably mostly the result of the shortening of the diastolic time interval with increasing heart rate whereas in patients with bioprosthetic valves an increase in functional valve area may contribute to the shortening of pressure half time during exercise.

[Hemodynamics of various heart valve prostheses]

Modern tilting disc and bileaflet prostheses, and bio-prostheses, perform similarly regarding pressure gradients, discharge coefficient and performance index; however, only bio-prostheses increase their opening area with increasing flow. Ball valve prostheses of the Starr-Edwards type perform less satisfactorily with higher pressure gradients and lower performance indices, which may result in less favorable long-term follow-up. Bio-prostheses show degenerative changes with increasing age which, over a period of 7-10 years, can lead to clinically relevant stenoses necessitating reoperation.

Long-term treatment of ventricular tachycardia with amiodarone in presence of severe left ventricular dysfunction

A group of 34 consecutive patients with coronary artery disease (n = 29) or dilated cardiomyopathy (n = 5) (3 women, 31 men, age 38-80 yr) who had severely impaired left ventricular function (left ventricular ejection fraction less than or equal to 40%) and high-grade ventricular ectopic activity (sustained or nonsustained ventricular tachycardia or ventricular fibrillation) were treated with amiodarone (mean dose: 206 mg/d) and followed for 1-117 (mean: 49) months. In the total group, there were seven sudden deaths, five deaths due to pump failure, one non-cardiac death, and two successful heart transplantations during follow-up. Thus the annual cardiac mortality in these carefully selected and followed patients was 8, 6%, the annual cardiac event rate was 10, 1%. The cumulative cardiac survival-rate was 62% after 5 years and 41% after 10 years. In five patients, treatment was interrupted after 10 to 43 months, three of the patients were alive at follow-up and two suffered cardiac death, resulting in an annual cardiac death rate of 12% in this subgroup of treatment. Based on the results of this retrospective analysis we conclude that in patients with low left ventricular ejection fraction and nonsustained or sustained ventricular tachycardia treated with low dose amiodarone, mortality was unexpectedly low. Thus, it may be the antiarrhythmic treatment to be considered in patients with ventricular tachycardia and severe left ventricular dysfunction.