Unmasked superoparaseptal pathway conduction due to atrial fibrillation in a patient with left ventricular dysfunction. Rapid recovery after successful radiofrequency ablation.

We report the case of a 56-year-old woman with newly diagnosed atrial fibrillation (AF) and severe left ventricular (LV) dysfunction caused by rapid conduction via an accessory pathway (AP), mimicking left bundle branch block, as the first clinical manifestation of Wolff-Parkinson-White (WPW) syndrome. Electrical cardioversion of the AF revealed a short PR interval and a delta wave, which was positive in leads I, II, aVL, and V2 and negative in lead V1 with a transition zone between V1 and V2. Radiofrequency catheter ablation of a superoparaseptal pathway was accompanied by rapid recovery from LV systolic dysfunction.

Catheter-based renal denervation for drug-resistant hypertension by using a standard electrophysiology catheter.

AIMS: The endovascular application of low-dose radiofrequency (RF) energy to the renal arteries results in effective ablation of sympathetic nerve fibres leading to a significant lowering of blood pressure (BP). This study aims to examine the feasibility and safety of renal denervation by the use of a standard electrophysiology (EP) catheter. METHODS AND RESULTS: Twelve patients (mean age 62±14 years, nine male) with drug resistant hypertension despite medical treatment with at least four antihypertensive drugs underwent renal denervation by using a standard steerable RF ablation catheter with a 7 Fr diameter (Marinr®; Medtronic Inc., Minneapolis, MN, USA). Low-power RF applications have been applied along the length of both renal arteries, consecutively. Assessment of 24 hour ambulatory BP was done at baseline, at one, and at three months following RF ablation. The mean reduction of 24 hour ambulatory BP was -11/-7 mmHg at one month and -24/-14 mmHg at three months (p<0.01 for systolic and p<0.03 for diastolic blood pressure) with unchanged medication. No vascular complications have been observed in the short-term follow-up. The renal function as assessed by serum creatinine and proteinuria remained unchanged from baseline. CONCLUSIONS: Our preliminary results indicate that the use of a standard RF ablation catheter is feasible and safe for sympathetic renal denervation as shown by a significant lowering of mean 24 hour ambulatory BP in comparison to baseline during short-term follow-up. Whether the use of a standard EP catheter for sympathetic renal denervation indeed improves the long-term outcome in resistant hypertension, however, remains to be investigated.

QRS duration and QTc interval are predictors of risk for ventricular arrhythmias during cardiac resynchronization therapy.

BACKGROUND AND OBJECTIVES: QRS duration (QRSd) and prolonged corrected QT interval (QTc) are associated with ventricular arrhythmic events. This study was designed to determine whether CRT by means of biventricular pacing alters the QTc and QRSd, and whether such changes are related to the risk of sustained ventricular tachyarrhythmias (sVTA). METHODS AND RESULTS: A total of 127 patients (102 men, mean age 63.9 +/- 8.9 years) with drug-resistant heart failure and QRS duration > or = 130 ms underwent CRT/CRT-ICD. The aetiology of the heart failure was ischaemic in 41 patients (32.3%). After a median follow-up of 24 months, 42 sVTA occurred in 35 patients (27.6%). Twenty-nine patients had a single sVTA, in five patients two sVTA and in one patient three sVTA occurred. The paced QTc was longer in sVTA patients (505 +/- 55 ms) compared with no sVTA patients (486 +/- 44 ms, P < or = 0.003). Similar responses for paced QRSd were observed (182 +/- 27 ms in sVTA patients vs 167 +/- 27 ms in no-sVTA patients, P < or = 0.03). This effect was independent from intrinsic QTc and QRSd and the aetiology of the heart failure. The mortality rate was significantly higher in patients with ventricular fibrillation and fast VT (P < or = 0.004) who experienced shock therapies. However, the sVTA were not the immediate cause of death. CONCLUSIONS: A pacing-induced increase in QTc and QRSd is related to sVTA in patients with CRT. Further studies are needed to determine whether optimization of CRT with the goal to achieve a narrow paced QRSd can reduce the occurrence of sVTA.

Left ventricular lead position and nonspecific conduction delay are predictors of mortality in patients during cardiac resynchronization therapy.

BACKGROUND: Cardiac resynchronization therapy (CRT) is an established treatment of severe systolic heart failure with intraventricular conduction delay. The influence on mortality of the left ventricular (LV) pacing site and the type of bundle-branch block during CRT is unclear. OBJECTIVES: This study investigates the clinical significance of LV lead position, as well as nonspecific conduction delay, in CRT. METHODS: 143 consecutive patients (mean age, 63.9 ± 8.9 years; 121 men) underwent implantation of a CRT device according to established criteria. At the time of implantation, the LV lead position and the type of bundle-branch block were recorded. The etiology of the heart failure was ischemic in 49 patients (34.3%) and nonischemic in 94 patients (65.7%). RESULTS: After a median follow-up of 19 months, 39 patients (27.3%) died, most of them (72%) of cardiovascular causes. The mortality was significantly higher in patients with an anterior or anterolateral LV lead position (P = 0.03). Multivariate analysis suggests that an anterior or anterolateral LV lead position, a nonspecific conduction delay, male sex, and a New York Heart Association functional class worse than III, are all independent predictors of mortality during the follow-up period. CONCLUSION: LV lead position and nonspecific conduction delay are predictors of mortality in patients during cardiac resynchronization therapy.