Unusual response to His-refractory atrial premature complex: What is the mechanism?

A 32-year-old woman underwent radiofrequency catheter ablation of narrow QRS tachycardia that was terminated with intravenous adenosine.

Endo/epicardial ablation of ventricular arrhythmias with contact force-sensing catheters in arrhythmogenic right ventricular dysplasia/cardiomyopathy.

OBJECTIVE: To control ventricular arrhythmia in arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C), ablation may be required both from the endocardial and epicardial side. In this study, we analyzed the results of contact force-sensing (CFS) catheters in the endo/epicardial ablation of ventricular arrhythmias in ARVD/C. METHODS: We included 17 patients with ARVD/C, 5 of whom had premature ventricular contractions (PVC), and the rest of them were admitted with a ventricular tachycardia (VT) storm, between September 2014 and October 2016. We divided patients into two groups: the PVC and VT groups. Irrigated CFS catheters (Smart Touch, Biosense Webster, Inc.) were utilized in all procedures. RESULTS: In the PVC group, the mean ratio of PVC during the 24-hour Holter monitoring was 31.8+-7.6%. The mean contact force during mapping and ablation in the right ventricle was 13+-1.2 and 12.8+-1.9 grams, respectively. The mean follow-up duration was 15+-3.1 months for the PVC group. The left ventricular ejection fraction improved in all patients (52.8+-10%). All patients in the VT group underwent endo/epicardial ablation, except one. The mean contact force during the endocardium and epicardium mapping was 12.5+-1.2 and 12.5+-4.6 grams, respectively. The mean contact force during ablation for the endocardium and epicardium was 12.1+-1.4 and 12.8+-1.9 grams, respectively. All clinical and non-clinical VTs were ablated successfully, except in 2 patients who still had non-clinical VTs. The mean follow-up was 15.5+-4.5 months. None of the VT patients experienced electrical storm or death. Two patients had single shock, and 1 patient had two shocks during the follow-up. CONCLUSION: Endo/epicardial ablation of ventricular arrhythmias with CFS catheters in ARVD/C seems to be promising.

Transesophageal and invasive electrophysiologic evaluation in children with Wolff-Parkinson-White pattern.

BACKGROUND: Risk stratification for Wolff-Parkinson-White (WPW) pattern either by noninvasive or invasive tests is important to determine whether an ablation is necessary or not. The aim was to compare noninvasive tests and invasive studies in a pediatric WPW population. METHODS: A total of 71 WPW patients (median age 14 years [interquartile range, 11-16 years]; 43 male) underwent Holter monitoring, exercise stress test (EST), and transesophageal electrophysiological study (TEEPS). In the case of a ≤270-ms effective refractory period of accessory pathway or induction of supraventricular tachycardia using TEEPS, patients were classified as high risk and underwent invasive electrophysiological study (EPS). RESULTS: Nine of 23 patients with low risk by Holter and eight of 26 patients with low risk by EST had high risk in TEEPS. Risky TEEPS results were detected in 42 of 71 patients and those patients underwent EPS. High-risk characteristic in EPS was detected in seven of nine patients with low risk by Holter and in seven of eight with low risk by EST. Both tests yielded moderate specificity (52-69%) and negative predictive value (61-69%) according to TEEPS. CONCLUSION: Holter and EST have low predictive value in WPW risk stratification. However, TEEPS and EPS are extremely valuable in WPW risk stratification. TEEPS may reveal important and useful results for WPW risk determination, especially in small children not having undergone EPS in order to avoid its complications.

Atrioventricular block induced by mad-honey intoxication: confirmation of diagnosis by pollen analysis.

An unusual type of food poisoning, mad-honey intoxication, can be observed in the Black Sea region of Turkey and various other parts of the world. It can occur after ingestion of grayanotoxin-contaminated honey produced from the nectar of Rhododendron ponticum and other plant species, chiefly of the Ericaceae and Sapindaceae families. Mad-honey intoxication can result in severe cardiac complications, such as complete atrioventricular block. The diagnosis is generally reached on the basis of the patient's history of honey intake. In this report, we describe the case of a patient who had mad-honey-related complete atrioventricular block; in this instance, the diagnosis was confirmed by a pollen analysis of the suspect honey.

Evaluation of atrial refractoriness immediately after percutaneous mitral balloon commissurotomy in patients with mitral stenosis and sinus rhythm.

BACKGROUND: Chronic atrial stretch and rheumatic inflammatory activity leads to atrial dilatation and conduction slowing, and this increases the susceptibility to atrial fibrillation (AF). The aim of this study was to examine the effects of changes in the chronic atrial stretch on atrial refractoriness in the early period after percutaneous mitral balloon commissurotomy (PMBC) in patients with mitral stenosis and sinus rhythm. METHODS: Twenty-five patients undergoing PMBC were enrolled in this study. We evaluated the changes in pulmonary arterial pressure (PAP), left atrial (LA) pressure, mean mitral diastolic gradient, and mitral valve area in addition to the changes in atrial effective refractory periods (AERPs), AERP dispersion, and intra-atrial and interatrial conduction times after PMBC. RESULTS: There were significant decreases in mean diastolic gradient, PAP, mean LA pressure, and LA size after PMBC. Accompanying these acute hemodynamic changes after PMBC, AERPs in high right atrium (HRA), distal coronary sinus (DCS), and right posterolateral (RPL) were found to be increased (P <.001), and AERP dispersion, PA(HIS) (an interval between P wave on the surface electrocardiogram and atrial electrogram at the His bundle site), and HRA-DCS intervals were significantly reduced after PMBC (P <.001). It was revealed with linear regression and correlation analysis that only the changes in AERP dispersion were correlated with changes in LA pressure. CONCLUSIONS: Relief of chronic atrial stretch results in an increase in AERPs and decrease in AERP dispersion, suggesting the potential reversibility of the electrophysiological features of chronic atrial dilatation. Our study emphasizes that an acute reduction of chronic atrial stretch in mitral stenosis resulted in favorable effects on atrial electrophysiological characteristics, and our results provide the first detailed insights into the electrophysiological changes after PMBC in patients with sinus rhythm.