Positional sleep disordered breathing in patients with arrhythmia. Should we advise our patients to avoid supine position during sleep?

BACKGROUND: Sleep disordered breathing [SDB] is a well-known problem in patients with cardiovascular diseases. Around 50% of pts. with SDB present positional sleep disordered breathing [PSDB]. AIMS: The aim of this study was the investigation of the frequency of PSDB in patients with different forms of arrhythmias. METHODS: We analyzed the presence of SDB in 53 pts. with diagnosed atrial fibrillation (paroxysmal or persistent), 88 pts. before ablation of ventricular ectopy and 110 pts. that had Holter monitoring due to the symptoms suggesting arrhythmia. RESULTS: Finally, we could collect all the data in 243 pts. - 150 men 93 women. AHI < 15 was recorded in 136 (56%) pts., AHI > 15 in 107 (44%) pts. Moderate sleep disordered breathing was diagnosed in 59 (24%) pts. (AHI 15-30), severe sleep disordered breathing (AHI > 30) was recognized in 48 (20%) pts. In all of the analyzed groups, AHI in supine position was significantly higher than in nonsupine position. PSDB was recorded in 55% of pts. with AHI > 15 and in 29% of pts. (n = 14) with AHI > 30. Percentage of time in supine position was an independent factor related with the presence of at least moderate or severe sleep disordered breathing. CONCLUSION: 1. Moderate or severe SDB is recorded in 44% of pts. with arrhythmias, almost 50% of them have positional SDB. 2. Percent of time of sleeping in supine position has an important independent impact on the presence of SDB. 3. Big studies should be conducted to verify if avoidance of sleeping in supine position may improve clinical outcome. CONDENSED ABSTRACT: Sleep disordered breathing SDB is a frequent problem of pts. with cardiovascular diseases. It may influence the prognosis. Moderate or severe SDB is recorded in 44% of pts. with arrhythmias, almost 50% of them have positional SDB. Percent of time of sleeping in supine position has an important independent impact on the presence of SDB. 3. Big studies should be conducted to verify if avoidance of sleeping in supine position may improve clinical outcome. What is new?

Troponin T Assessment Allows for Identification of Mutation Carriers among Young Relatives of Patients with LMNA-Related Dilated Cardiomyopathy.

Background:LMNA-related dilated cardiomyopathy (LMNA-DCM) caused by mutations in the lamin A/C gene (LMNA) is one of the most common forms of hereditary DCM. Due to the high risk of mutation transmission to offspring and the high incidence of ventricular arrhythmia and sudden death even before the onset of heart failure symptoms, it is very important to identify LMNA-mutation carriers. However, many relatives of LMNA-DCM patients do not report to specialized centers for clinical or genetic screening. Therefore, an easily available tool to identify at-risk subjects is needed. Methods: We compared two cohorts of young, asymptomatic relatives of DCM patients who reported for screening: 29 LMNA mutation carriers and 43 individuals from the control group. Receiver operating characteristic (ROC) curves for potential indicators of mutation carriership status were analyzed. Results: PR interval, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and high-sensitivity cardiac troponin T (hscTnT) serum levels were higher in the LMNA mutation carrier cohort. Neither group differed significantly with regard to creatinine concentration or left ventricular ejection fraction. The best mutation carriership discriminator was hscTnT level with an optimal cut-off value at 5.5 ng/L, for which sensitivity and specificity were 86% and 93%, respectively. The median hscTnT level was 11.0 ng/L in LMNA mutation carriers vs. <3.0 ng/L in the control group, p < 0.001. Conclusions: Wherever access to genetic testing is limited, LMNA mutation carriership status can be assessed reliably using the hscTnT assay. Among young symptomless relatives of LMNA-DCM patients, a hscTnT level >5.5 ng/L strongly suggests mutation carriers.

High-resolution esophageal manometry with ECG monitoring for management of premature ventricular complexes-associated dysphagia.

We report a novel technique for diagnosing a new cause of esophageal dysphagia in a patient without organic heart and esophageal disease. A coincidence between intermittent esophageal dysphagia and cardiac arrhythmia, frequent premature ventricular complexes (PVC) were confirmed by clinical observation, simultaneous ECG monitoring, and motility study. High-resolution esophageal manometry (HRM) revealed abnormal peristaltic waves only during frequent PVC. Abnormal peristaltic waves and PVC disappeared simultaneously and completely within 15 min after intravenous infusion of antiarrhythmic agent (140 mg propafenone). Oral treatment with antiarrhythmic drugs was not tolerated or ineffective. Complete remission of PVC and dysphagia was achieved immediately after radiofrequency catheter ablation of arrhythmogenic focus located in the right ventricular outflow tract. This case demonstrates a new technique for the management of a syndrome called "PVC-associated dysphagia" that can be mediated by cardioesophageal reflex. Interdisciplinary cooperation and simultaneous HRM with ECG monitoring may confirm the diagnosis and guide effective treatment.

A combination of quinidine/mexiletine reduces arrhythmia in dilated cardiomyopathy in two patients with R814W SCN5A mutation.

SCN5A gene mutations are described in 2% of patients with dilated cardiomyopathy (DCM) and different rhythm disturbances, including multifocal ectopic Purkinje-related premature contractions. Recent data indicate that sodium channel blockers are particularly effective monotherapy in carriers of the R222Q SCN5A variant. Our purpose is to describe the effectiveness of antiarrhythmic treatment in a family with genetically determined arrhythmogenic DCM associated with the R814W variant in the SCN5A gene. We examined a family with arrhythmogenic DCM (multifocal ectopic Purkinje-related premature contractions phenotype, atrial tachyarrhythmias, automatism, and conduction disorders) and described antiarrhythmic treatment efficacy in heart failure symptoms reduction and myocardial function improvement. We found a heterozygotic mutation R814W in SCN5A by whole exome sequencing in the proband and confirmed its presence in all affected subjects. There were two sudden cardiac deaths and one heart transplantation among first-degree relatives. The 58-year-old father and his 37-year-old daughter had full spectrum of symptoms associated with R814W SCN5A mutation. Both had implanted cardioverter defibrillator. In the father, adding mexiletine to quinidine therapy reduced ventricular arrhythmia (50-60% â†’ 6-8% of whole rhythm) and reverted long-standing atrial fibrillation to sinus rhythm. In the daughter, mexiletine and overdrive pacing were effective in ventricular arrhythmia reduction (25% â†’ 0.01%). Because of a growing number of atrial fibrillation recurrences, a reduced dose of quinidine (subsequently flecainide) was added, resulting in arrhythmia significant reduction. In both cases, antiarrhythmic effectiveness correlated with clinical improvement. In SCN5A R814W-associated DCM, a combination of Class I antiarrhythmics and overdrive pacing is an effective treatment of severe ventricular and atrial arrhythmias.

Radiofrequency catheter ablation of accessory pathways in patients with Ebstein's anomaly: At 8 years of follow-up.

BACKGROUND: Data regarding long-term follow-up of radiofrequency catheter ablation (RFCA) of accessory pathways (APs) in patients with Ebstein's anomaly (EA) are limited. The procedures are challenging due to multiple or wide APs. METHODS: Analysis was performed on clinical and periprocedural data of patients with EA referred to the centre in order to perform catheter ablation of AP. The group consisted of 22 patients (female 40.9%, mean age 33.6 ± 19.1 years). The follow-up utilized electrocardiogram and Holter monitoring. RESULTS: Twenty-two patients had 33 accessory pathways (8 patients had multiple APs, 11 patients broad AP). Twenty-nine different arrhythmias were ablated: 20 orthodromic atrioventricular reciprocating tachycardia (O-AVRT), 5 antidromic atrioventricular reciprocating tachycardia (A-AVRT), 3 slow/ fast atrioventricular nodal reentry tachycardia (s/f AVNRT) and 1 cavotricuspid-isthmus-dependent atrial flutter (CTI-AFL). In 3 (13.6%) patients multiple ablation targets for RFCA ablation were observed. The acute procedural success rate after the first RFCA performed was: 100% for AVNRT, 77.3% for APs and 50.0% for CTI-AFL ablation. Follow-up (mean 95.7 ± 49.8 months) was completed in 86.4% of patients. One patient had paroxysmal atrial fibrillation not targeted during ablation. One patient died due to heart failure 12 years after RFCA. Three patients who underwent RFCA of accessory pathways in the mid-1990s were lost in follow-up. CONCLUSIONS: Radiofrequency ablation in patients with EA is challenging but safe and have a high short-term as well as long-term success rate.