Second Micra leadless pacemaker implantation by using intracardiac echocardiography

The strategy after battery depletion was not established in Micra leadless pacemaker system (Micra). There are still some concerns in the 2nd Micra implantation, such as the mechanical interaction between both devices. The position of the 2nd Micra should be placed apart from the 1st Micra. We present a case of 1st Micra battery depletion who successfully underwent the 2nd Micra implantation under the intracardiac echo guidance. In our case, intracardiac echo was a very effective tool for confirming the location of Micra implantation.

Pediatric hypertrophic cardiomyopathy caused by a novel TNNI3 variant

TNNI3 is a gene that causes hypertrophic cardiomyopathy (HCM). A 14-year-old girl who was diagnosed with nonobstructive HCM presented with cardiopulmonary arrest due to ventricular fibrillation. Genetic testing revealed a novel de novo heterozygous missense variant in TNNI3, NM_000363.5:c.583A>T (p.Ile195Phe), which was determined to be the pathogenic variant. The patient exhibited progressive myocardial fibrosis, left ventricular remodeling, and life-threatening arrhythmias. Genetic testing within families is useful for risk stratification in pediatric HCM patients.

Feasibility of a novel atrial mechanical sensing method for leadless atrioventricular synchronous pacing

INTRODUCTION

Few studies have demonstrated a high degree of atrioventricular (AV) synchrony with a new leadless pacemaker called Micra AV. Our group previously reported a new and unique sensing method. We believe that this novel sensing method, "Simplified A3 method," might facilitate better AV synchrony than a conventional sensing method in almost all cases with Micra AV implantation.

METHODS

We conducted a non-randomized retrospective study comparing the two pacing methods at two centers. From December 1, 2021 to October 31, 2022, Micra AV was implanted for 32 patients at the two centers. Twenty of the 32 patients with sinus rhythm and complete AV block were included in this study. In Group 1, the conventional setting was programmed as follows: auto A3 threshold, auto A3 window-end (WE), and auto A4 threshold turned on during hospitalization. In Group 2, the "Simplified A3 method" was programmed as follows: auto A3 threshold and auto A3WE turned off. Instead, an intentionally prolonged A3WE (850-1000 ms) and low A3 threshold (A3 signal amplitude + 0.5-1.0 m/s2) were programmed.

RESULTS

Twenty patients were analyzed. In Group 2, AV synchrony (%AMVp) was significantly higher at the first outpatient clinic (63.0 ± 5.7% vs 81.0 ± 4.2%, p = .03). A3 threshold was significantly lower in Group 2 (5.9 ± 0.7 m/s2, p < .05 vs 2.3 ± 0.5 m/s2, p < .05).

CONCLUSION

Our novel sensing method might be a more feasible sensing method for obtaining higher AV synchrony than the conventional algorithm.

Nutritional Status and Sleep Quality Are Associated with Atrial Fibrillation in Patients with Obstructive Sleep Apnea: Results from Tokyo Sleep Heart Study

The prevalence of obstructive sleep apnea (OSA) in patients with atrial fibrillation (AF) has been observed to be much higher than in control participants without AF. Limited data exist regarding the prevalence of AF in patients with OSA. The clinical characteristics, nutritional status, and sleep parameters associated with AF in patients with OSA remain unclear. In this study, we aimed to determine the prevalence and factors associated with AF in patients with OSA from a large Japanese sleep cohort (Tokyo Sleep Heart Study). This was a single-center explorative cross-sectional study. Between November 2004 and June 2018, we consecutively recruited 2569 patients with OSA who underwent an overnight full polysomnography at our hospital. They were assessed using a 12-lead ECG and echocardiography. The clinical characteristics, sleep parameters, and medical history were also determined. Of the OSA patients, 169 (6.6%) had AF. Compared with the non-AF patients, OSA patients with AF were older and male, and they had higher prevalence of a history of alcohol consumption, hypertension, chronic kidney disease, and undernutrition, as well as a reduced ejection fraction. With regard to the sleep study parameters, OSA patients with AF had reduced slow-wave sleep and sleep efficiency, as well as higher periodic limb movements. There were no significant differences in the apnea-hypopnea index or hypoxia index between the two groups. The logistic regression analysis demonstrated that age (OR = 4.020; 95% CI: 1.895-8.527; p < 0.001), a history of alcohol consumption (OR = 2.718; 95% CI: 1.461-5.057; p = 0.002), a high CONUT score (OR = 2.129; 95% CI: 1.077-4.209; p = 0.030), and reduced slow-wave sleep (OR = 5.361; 95% CI: 1.505-19.104; p = 0.010) were factors significantly related to AF. The prevalence of AF in patients with OSA was 6.6%. Age, a history of alcohol consumption, undernutrition, and reduced sleep quality were independent risk factors for the presence of AF in patients with OSA, regardless of the severity of OSA.

Registry for Evaluating Healthy Life Expectancy and Long-Term Outcomes after Catheter Ablation of Atrial Fibrillation in the Very Elderly (REHEALTH AF) study: rationale and design of a prospective, multicentre, observational, comparative study

INTRODUCTION

Data are lacking on the extent to which patients with non-valvular atrial fibrillation (AF) who are aged ≥80 years benefit from ablation treatment. The question pertains especially to patients' postablation quality of life (QoL) and long-term clinical outcomes.

METHODS AND ANALYSIS

We are initiating a prospective, registry-based, multicentre observational study that will include patients aged ≥80 years with non-valvular AF who choose to undergo treatment by catheter ablation and, for comparison, such patients who do not choose to undergo ablation (either according to their physician's advice or their own preference). Study subjects are to be enrolled from 52 participant hospitals and three clinics located throughout Japan from 1 June 2022 to 31 December 2023, and each will be followed up for 1 year. The planned sample size is 660, comprising 220 ablation group patients and 440 non-ablation group patients. The primary endpoint will be the composite incidence of stroke/transient ischaemic attack (TIA) or systemic embolism (SE), another cardiovascular event, major bleeding and/or death from any cause. Other clinical events such as postablation AF recurrence, a fall or bone fracture will be recorded. We will collect standard clinical background information plus each patient's Clinical Frailty Scale score, AF-related symptoms, QoL (Five-Level Version of EQ-5D) scores, Mini-Mental State Examination (optional) score and laboratory test results, including measures of nutritional status, on entry into the study and 1 year later, and serial changes in symptoms and QoL will also be secondary endpoints. Propensity score matching will be performed to account for covariates that could affect study results.

ETHICS AND DISSEMINATION

The study conforms to the Declaration of Helsinki and the Ethical Guidelines for Clinical Studies issued by the Ministry of Health, Labour and Welfare, Japan. Results of the study will be published in one or more peer-reviewed journals.

TRIAL REGISTRATION NUMBER

UMIN000047023.

A case of short-coupled variant of Torsade de Pointes with bystander early repolarization in inferior leads

The presence of J waves in cases of ventricular fibrillation (VF) is known to be a risk for sudden cardiac death. Recently, the effectiveness of radiofrequency catheter ablation (RFCA) for early repolarization syndrome (ERS) has been reported.The patient is a 30-year-old male with elevated J waves of 0.1 mV in the inferior leads, who had previously developed VF and undergone implantable cardioverter defibrillator (ICD) implantation. Because the VF from short coupled premature ventricular contraction (PVC) was presented, the RFCA of the triggered PVC was attempted. But it was unsuccessful due to no inducibility of the triggered PVC. After that, despite anti-arrythmia drug treatment, appropriate ICD shock for VF was observed. Although we decided to do a second ablation and evaluated epicardial arrhythmia substrate, no specific findings of early repolarization syndrome were found in the electrophysiological study. Finally, we considered that the cause of VF was short-coupled variant of Torsade de Pointes, and PVC ablation was performed. VF has not occurred since. We consider that this is a rare case to evaluate the epicardial arrhythmogenic substrate of J wave.

Learning objective

Ablation of the epicardial arrhythmogenic substrate in patients with early repolarization syndrome (ERS) has been shown to be effective, but the relationship between abnormal epicardial potentials and the pathophysiology is unclear. In this case, J-wave and epicardial delayed potentials were not considered to represent obvious arrhythmogenic substrates. Ablation of the triggered premature ventricular contraction may be effective in ERS without apparent abnormal potentials.

The Utility of a Lewis Lead for Distinguishing Atrioventricular Reentrant Tachycardia from Typical Atrioventricular Nodal Reentrant Tachycardia

Objective The Lewis lead configuration is an alternative bipolar chest lead and it can help detect atrial activity. The utility of the Lewis lead to distinguish orthodromic atrioventricular reentrant tachycardia (AVRT) from typical atrioventricular nodal reentrant tachycardia (AVNRT) by visualizing the apparent retrogradely conducted P waves was investigated. Methods Forty-four patients with paroxysmal supraventricular tachycardia (PSVT) were included in this study. All patients had PSVT documented by an electrocardiogram (ECG) and underwent an electrophysiological study (EPS). During tachycardia, an ECG recording was performed using a Lewis lead with the electrode on the right aspect of the sternum at the second intercostal space instead of the right arm and the electrode on the fourth intercostal space instead of the left arm. The ECG parameters during tachycardia were compared between AVRT and AVNRT. Results Fourteen patients were diagnosed with AVRTs and 30 with typical AVNRTs on EPS. The positive P wave could be seen in the Lewis lead configuration in 9 of 14 patients with AVRTs and 21 of 30 patients with AVNRTs. P waves were more often visible in the Lewis lead configuration than in the standard leads (66% vs. 45%). The RP interval was significantly longer for AVRTs than for AVNRTs (88±17 vs. 154±34 ms, p<0.001), which yields 89% sensitivity and 71% specificity for distinguishing these 2 tachyarrhythmias with a cut-off point of 100 ms. Conclusion A Lewis lead configuration may help to make an accurate diagnosis among the reentrant supraventricular tachycardias prior to procedures, owing to its ability to locate P waves.

Different Determinants of the Recurrence of Atrial Fibrillation and Adverse Clinical Events in the Mid-Term Period After Atrial Fibrillation Ablation

BACKGROUND

It is unclear whether there are differences in the clinical factors between atrial fibrillation (AF) recurrence and adverse clinical events (AEs), including stroke/transient ischemic attack (TIA), major bleeding, and death, after AF ablation.Methods and Results:We examined the data from a retrospective multicenter Japanese registry conducted at 24 cardiovascular centers between 2011 and 2017. Of the 3,451 patients (74.1% men; 63.3±10.3 years) who underwent AF ablation, 1,046 (30.3%) had AF recurrence and 224 (6.5%) suffered AEs (51 strokes/TIAs, 71 major bleeding events, and 36 deaths) over a median follow-up of 20.7 months. After multivariate adjustment, female sex, persistent and long-lasting persistent AF (vs. paroxysmal AF), and stepwise increased left atrial diameter (LAd) quartiles were significantly associated with post-ablation recurrences. A multivariate analysis revealed that an age ≥75 years (vs. <65 years), body weight <50 kg, diabetes, vascular disease, left ventricular (LV) ejection fraction <40% (vs. ≥50%), Lad ≥44 mm (vs. <36 mm), and creatinine clearance <50 mL/min were independently associated with AE incidences, but not with recurrences.

CONCLUSIONS

This study disclosed different determinants of post-ablation recurrence and AEs. Female sex, persistent AF, and enlarged LAd were determinants of post-ablation recurrence, whereas an old age, comorbidities, and LV and renal dysfunction rather than post-ablation recurrence were AEs determinants. These findings will help determine ablation indications and post-ablation management.

Clinical outcomes of ablation versus non-ablation therapy for atrial fibrillation in Japan: analysis of pooled data from the AF Frontier Ablation Registry and SAKURA AF Registry

Whether ablation for atrial fibrillation (AF) is, in terms of clinical outcomes, beneficial for Japanese patients has not been clarified. Drawing data from 2 Japanese AF registries (AF Frontier Ablation Registry and SAKURA AF Registry), we compared the incidence of clinically relevant events (CREs), including stroke/transient ischemic attack (TIA), major bleeding, cardiovascular events, and death, between patients who underwent ablation (n = 3451) and those who did not (n = 2930). We also compared propensity-score matched patients (n = 1414 in each group). In propensity-scored patients who underwent ablation and those who did not, mean follow-up times were 27.2 and 35.8 months, respectively. Annualized rates for stroke/TIA (1.04 vs. 1.06%), major bleeding (1.44 vs. 1.20%), cardiovascular events (2.15 vs. 2.49%) were similar (P = 0.96, 0.39, and 0.35, respectively), but annualized death rates were lower in the ablation group than in the non-ablation group (0.75 vs.1.28%, P = 0.028). After multivariate adjustment, the risk of CREs was statistically equivalent between the ablation and non-ablation groups (hazard ratio [HR] 0.89, 95% confidence interval [CI] 0.71-1.11), but it was significantly low among patients who underwent ablation for paroxysmal AF (HR 0.68 [vs. persistent AF], 95% CI 0.49-0.94) and had a CHA₂DS₂-VASc score  < 3 (HR 0.66 [vs. CHA₂DS₂-VASc score ≥ 3], 95% CI 0.43-0.98]). The 2-year risk reduction achieved by ablation may be small among Japanese patients, but AF ablation may benefit those with paroxysmal AF and a CHA₂DS₂-VASc score < 3.

P3535Prognostic value of congestion status by bioelectrical impedance analysis and natriuretic peptide levels in acute heart failure with preserved versus reduced left ventricular ejection fraction

Background

N-terminal pro-brain natriuretic peptide (NT-proBNP) is a well-known predictor of acute heart failure (HF). Congestion volume status estimated by bioelectrical impedance analysis (BIA) is also associated with adverse cardiovascular events in HF patients. However, it is unclear whether these biomarkers reflecting pathophysiological pathways are different between HF with preserved (HFpEF) and reduced ejection fraction (HFrEF).

Purpose

The aim of this study was to investigate whether the prognostic value of NT-proBNP and extracellular water/free fat mass (ECW%) assessed by BIA is different between HFrEF and HFpEF in acute HF patients.

Methods and results

One hundred-and-forty-three patients admitted for acute HF between November 2013 and January 2015 were estimated for NT-proBNP levels and ECW% by BIA on admission. A total of 49 HFrEF (LVEF<40%) and 75 HFpEF (LVEF≥50%) patients were included in this study (mean age: 76±14 years, male: 63%). The median of NT-proBNP levels in HFrEF patients was higher than in HFpEF (6022 [IQR: 2531–9163] pg/mL and 3179 [1076–6054] pg/mL, respectively, p=0.012). Conversely, ECW% was similar between HFrEF and HFpEF (29.0 [25.7–33.7] % and 31.7 [27.3–38.8] %, respectively, p=0.088). The primary endpoint was the composite of all-cause mortality and/or hospitalisation due to HF. During a median follow-up of 5.9 months, 16 (35.6%) and 35 (50.7%) patients were observed to have composite events in HFrEF and HFpEF, respectively, (p=0.111). Elevated NT-proBNP levels in HFrEF patients were associated with an increased risk of composite events after adjustment for traditional risk factors (hazard ratio [HR]: 2.39; 95% Confidence interval [CI]; 1.04–5.47; p=0.040), but not in HFpEF (p=0.063). Meanwhile, a high ECW% in HFrEF patients was associated with increasing composite events risk (HR: 3.30; 95% CI; 1.32–8.25; p=0.011), as well as in HFpEF patients (HR: 1.62; 95% CI; 1.03–2.55; p=0.037). Furthermore, the ECW% in addition to NT-proBNP in HFpEF patients resulted in a significant improvement in prediction for composite events (net reclassification improvement 0.67 [95% CI 0.24–1.11]; p=0.002 and integrated discrimination improvement 0.12 [0.004–0.20]; p=0.004).

Conclusion

Elevated levels of NT-proBNP in acute HF were predictive for mortality and hospitalisation due to HF in HFrEF but may not be for HFpEF patients, and ECW% had a better predictive value than NT-proBNP in HFpEF patients.

The usefulness of the consensus clinical diagnostic criteria in Brugada syndrome

BACKGROUND

Consensus statements were proposed for the diagnosis of Brugada syndrome (BS). The clinical diagnostic criteria were defined as documented ventricular fibrillation or ventricular tachycardia (VT), family history of sudden cardiac death at <45 years, diagnostic ECGs of family members, inducibility of VT during electrophysiological study, syncope or nocturnal agonal respiration. The clinical validation of these criteria is still missing. Methods and results 280 patients (41 ± 18 years, male: 168 pts) with diagnostic coved type I ECG were included. Consensus clinical diagnostic criteria were present in 244 (87%) patients (40 ± 18 y, 142 males). In 36 pts (13% of the 280 pts, 51 ± 12 years, 27 males) consensus clinical diagnostic criteria were not met. Nine patients (25%) presented with spontaneous type I ECG. Ten of the 36 patients (28%) had a history of atrial fibrillation and 13 (36%) had conduction disease on the baseline ECG. In 23 patients (64%) family screening was not performed. Two of the 36 patients had undocumented syncope during follow-up. Univariate analysis showed no significant difference in event free survival between patients with or without consensus clinical diagnostic criteria.

CONCLUSIONS

In a significant number of patients with diagnostic ECG pattern the current diagnostic criteria for BS are not met. These patients have frequently spontaneous type I ECG and clinical signs of Brugada syndrome as paroxysmal atrial fibrillation or conduction disturbances. Our results suggest that in patients with a diagnostic type I ECG pattern the current clinical consensus diagnostic criteria have limited added diagnostic value.

Added value of transoesophageal echocardiography during transseptal puncture performed by inexperienced operators

AIMS

Transseptal puncture (TP) appears to be safe in experienced hands; however, it can be associated with life-threatening complications. The aim of our study was to demonstrate the added value of routine use of transoesophageal echocardiography (TEE) for the correct positioning of the transseptal system in the fossa ovalis, thus potentially preventing complications during fluoroscopy-guided TP performed by inexperienced operators.

METHODS AND RESULTS

Two hundred and five patients undergoing pulmonary vein isolation procedure (PVI) for drug-resistant paroxysmal or persistent atrial fibrillation were prospectively included. When the operator (initially blinded to TEE) assumed that the transseptal system was in a correct position according to fluoroscopical landmarks, the latter was then checked with TEE unblinding the physician. If necessary, further refinement of the catheter position was performed. Refinement >10 mm, or in case of catheter pointing directly at the aortic root or posterior wall were considered as major repositioning. Thirty-four patients required major repositioning. Regression analysis revealed age (P: 0.0001, Wald: 12.9, 95% confidence interval: 1.04-1.16), left atrial diameter (P: 0.01, Wald: 6.6, 95% confidence interval: 1.04-1.34), previous PVI (P: 0.01, Wald: 6.3, 95% confidence interval: 1.31-8.76), and atrial septal thickness (P: 0.03, Wald: 4.5, 95% confidence interval: 1.05-3.4) as independent predictors of major revision with TEE.

CONCLUSION

Routine 2D TEE in addition to traditional fluoroscopic TP appears to be very useful to guide the TP assembly in a correct puncture position and thus, to avoid TP-related complications. However, further randomized prospective comparative studies are necessary to support these suggestions.

You can't judge a book by its cover: a pseudo 1st degree A-V block in apparent absence of retrograde conduction

We report 3 tracings from an electrophysiological study in which the appearance of a pseudo 1st degree A-V block helped to unmask the presence of a retrograde conduction, previously unrecognized. Our case highlights the importance in specific cases to have more than 2 intracardiac tracings during an electrophysiological study.

The value of a family history of sudden death in patients with diagnostic type I Brugada ECG pattern

AIMS

We sought to investigate the value of a family history of sudden death (SD) in Brugada syndrome (BS).

METHODS AND RESULTS

Two hundred and eighty consecutive patients (mean age: 41 ± 18 years, 168 males) with diagnostic type I Brugada ECG pattern were included. Sudden death occurred in 69 (43%) of 157 families. One hundred and ten SDs were analysed. During follow-up VF (ventricular fibrillation) or SD-free survival rate was not different between patients with or without a family history of SD of a first-degree relative, between patients with or without a family history of multiple SD of a first-degree relative at any age and between patients with or without a family history of SD in first-degree relatives ≤35 years. One patient had family history of SD of two first-degree relative ≤35 years with arrhythmic event during follow-up. In univariate analysis male gender (P = 0.01), aborted SD (P < 0.001), syncope (P = 0.04), spontaneous type I ECG (P < 0.001), and inducibility during electrophysiological (EP) study (P < 0.001) were associated with worse prognosis. The absence of syncope, aborted SD, spontaneous type I ECG, and inducibility during EP study was associated with a significantly better prognosis (P < 0.001).

CONCLUSION

Family history of SD is not predictive for future arrhythmic events even if considering only SD in first-degree relatives or SD in first-degree relatives at a young age. The absence of syncope, aborted SD, spontaneous type I ECG, and inducibility during EP study is associated with a good five-year prognosis.

Atrial fibrillation ablation: a single center comparison between remote magnetic navigation, cryoballoon and conventional manual pulmonary vein isolation

BACKGROUND

The aim of the study was to compare in our center the effect of different ablation techniques on intermediate term freedom from atrial fibrillation (AF) or atrial tachycardia (AT) in patients affected by refractory AF.

METHODS AND RESULTS

We retrospectively selected 94 patients who underwent AF ablation in our electrophysiological laboratory from June 2007 to December 2009. 29 patients underwent manual circumferential pulmonary vein isolation (mCPVI), 35 underwent remote magnetic navigation assisted CPVI (rmtCPVI) and 30 cryoballoon CPVI (cCPVI). Antiarrhythmic drugs were systematically stopped 2 months after the procedure (end of the "blanking period"). At a mean follow-up of 12,64 ± 6,41 months (range 2-31), the success rate for mCPVI group was 65.5% (19 patients), 66.7 % (20 patients) for the rmtCPVI group and 65.7 % (23 patients) for the cCPVI group (p = 0.625). Procedural and fluoroscopy times were significantly reduced in the cCPVI group (both p < 0.001). Univariate Cox regression showed that no clinical variables were independently associated with recurrence.

CONCLUSIONS

In our center's experience cCPVI and rmtCPVI have been demonstrated to be as effective as mCPVI. cCPVI seemed to be associated with lower procedural and fluoroscopy times.

Accelerated idioventricular rhythm during ajmaline test: a case report

We present an unusual transient pro-arrhythmic effect of ajmaline in a patient with resuscitated cardiac arrest and a left ventricular apical aneurysm. We discuss the clinical presentation and the possible physio-pathological explanation for this new pro-arrhythmic effect linked to administration of intravenous ajmaline.

Cryoballoon ablation for paroxysmal atrial fibrillation in septuagenarians: a prospective study

AIMS

To evaluate the effects of pulmonary vein isolation (PVI) in terms of feasibility, safety and success rate on a midterm follow-up period in septuagenarians undergoing ablation with the Arctic Front Cryoballoon for atrial fibrillation (AF).

METHODS AND RESULTS

We prospectively enrolled 21 patients aged 70 years or older (14 male; age 73 ± 2.5 years) elected to circumferential PVI with the 28mm cryoballoon for symptomatic drug resistant paroxysmal AF. A total number of 82 pulmonary veins (PV) were evidenced. Successful isolation could be obtained in all 82 (100%) PV ostia at the end of procedure. No major complication occurred during procedure. At a mean follow-up of 11.5 ± 4.7 months following ablation, 62% of patients did not present recurrence of atrial arrhythmias.

CONCLUSION

Cryoballoon ablation may be feasible and safe in older patients. Moreover a large proportion of the latter did not present AF recurrence during follow-up.

Stepwise transition of 2:1 atrio-ventricular block to 1:1 conduction induced by ventricular premature beats in a patient with atypical AVNRT

A 55-year-old man with a 2-year history of recurrent paroxysmal palpitations and with an electrocardiogram documentation of atypical atrioventricular nodal re-entrant tachycardia (AVNRT) was referred to us for catheter ablation. After an initial ablation attempt, several episodes of atypical AVNRT were induced. During one of these episodes, we documented a stepwise transition of 2:1 atrioventricular block to 1:1 conduction, following two single ventricular premature beats. This phenomenon confirmed the functional nature of the AV block during AVNRT and indirectly its infra-nodal location.

Transseptal puncture for atrial fibrillation ablation in a patient with previous Tirone David intervention: the role of real-time 3D transesophageal echocardiography guidance

In this case report we describe the important role of real-time three-dimensional transesophageal echocardiography guidance in performing double transseptal puncture for atrial fibrillation ablation in a patient who underwent a previous Tirone David intervention.

Novel trans-septal approach using a Safe Sept J-shaped guidewire in difficult left atrial access during atrial fibrillation ablation

Nowadays, trans-septal (TS) puncture is a relatively safe and straightforward procedure in experienced hands. However, in the presence of a thick, aneurysmatic or extremely elastic fossa ovalis crossing the septum might be challenging. We here describe the use of a novel guidewire that permits easy and safe 'over the wire' TS access during atrial fibrillation ablation.

Clinical study comparing bleeding and nonbleeding rectal varices

BACKGROUND AND STUDY AIMS

Although rectal varices constitute an important cause of lower digestive tract bleeding in patients with portal hypertension, the etiology and pathology of rectal varices remains controversial, and adequate treatment for rectal varices has yet to be established. In this study, we evaluated rectal varices to identify any common characteristics of varices which are susceptible to hemorrhage.

PATIENTS AND METHODS

The patients included 40 individuals with rectal varices among 425 patients with portal hypertension who had been treated in our institution. We retrospectively examined patient data regarding underlying hepatic diseases, hepatic function and endoscopic findings with regard to varices.

RESULTS

Bleeding from rectal varices occurred in 15 of the 40 patients. Although the prevalence of hemorrhage tended to increase with exacerbation of hepatic dysfunction, no significant differences were found. Similarly, although the incidence of hemorrhage tended to be somewhat higher in patients who had undergone any treatment for complicated esophageal varices than in patients who had not, no significant difference was found. The prevalence of hemorrhage from rectal varices significantly increased in rectal varices of more advanced form, and the prevalence was significantly higher in patients with positive "red color" sign.

CONCLUSIONS

The prevalence of hemorrhage from rectal varices was significantly higher in patients with rectal varices of advanced form and/or with a positive "red color" sign.

Renal damage and salt-dependent hypertension in aged transgenic mice overexpressing endothelin-1

The recent development of endothelin-1 (ET-1) antagonists and their potential use in the treatment of human disease raises questions as to the role of ET-1 in the pathophysiology of such cardiovascular ailments as hypertension, heart failure, renal failure and atherosclerosis. It is still unclear, for example, whether activation of an endogenous ET-1 system is itself the primary cause of any of these ailments. In that context, the phenotypic manifestations of chronic ET-1 overproduction may provide clues about the tissues and systems affected by ET-1. We therefore established two lines of transgenic mice overexpressing the ET-1 gene under the direction of its own promoter. These mice exhibited low body weight, diminished fur density and two- to fourfold increases in the ET-1 levels measured in plasma, heart, kidney and aorta. There were no apparent histological abnormalities in the visceral organs of young (8 weeks old) transgenic mice, nor was their blood pressure elevated. In aged (12 months old) transgenic mice, however, renal manifestations, including prominent interstitial fibrosis, renal cysts, glomerulosclerosis and narrowing of arterioles, were detected. These pathological changes were accompanied by decreased creatinine clearance, elevated urinary protein excretion and salt-dependent hypertension. It thus appears that mild, chronic overproduction of ET-1 does not primarily cause hypertension but triggers damaging changes in the kidney which lead to the susceptibility to salt-induced hypertension.

Elevated sympathetic nervous activity in mice deficient in alphaCGRP

alpha-Calcitonin gene-related peptide (alphaCGRP) is a pleiotropic neuropeptide implicated in a variety of physiological processes. To better understand the biological functions of alphaCGRP, we developed an alphaCGRP-null mouse model using a gene targeting approach. Recordings of mean arterial pressure (MAP) and heart rate (HR) showed that basal MAP and HR were significantly higher in both anesthetized and conscious, unrestrained alphaCGRP-null mice than in corresponding wild-type mice. The elevated MAP in alphaCGRP-null mice was shown to be the result of elevated peripheral vascular resistance by alpha-adrenergic blockade with prazosin and by transthoracic echocardiogram, which revealed no significant differences between alphaCGRP-null and wild-type mice in the stroke volume, fractional shortening, and ejection fraction. Moreover, evaluation of autonomic nervous activity by measuring HR after pretreatment of atropine and/or atenolol and by analyzing arterial baroreceptor reflexes showed sympathetic nervous activity to be significantly elevated in alphaCGRP-null mice; elevated levels of urinary catecholamine metabolites and decreased HR variability in mutant mice were also consistent with that finding. These findings suggest that alphaCGRP contributes to the regulation of cardiovascular function through inhibitory modulation of sympathetic nervous activity.