Thorben Koenig

Ablation of Typical Right Atrial Flutter in Patients with Pulmonary Hypertension

BACKGROUND RF ablation for cavotricuspid isthmus (CTI) dependent flutter is an established therapy. Right atrial hypertrophy and enlargement are associated with the occurrence of cavotricuspid isthmus dependent flutter. Therefore, patients with pulmonary hypertension (PAH) are prone to atrial arrhythmias like cavotricuspid isthmus dependent flutter. However, the influence of PAH on typical atrial flutter ablation procedure has not been systematically examined. METHODS In a retrospective single-centre analysis data of patients undergoing an ablation procedure for cavotricuspid isthmus dependent flutter between January 2007 and October 2009 at Hannover Medical School, Germany were analysed. Only procedures performed by experienced electrophysiologists with an 8mm RF-ablation catheter were included. Data for 196 patients were analysed. Thirty-eight patients were identified with PAH and were compared to 158 patients without PAH for procedural ablation parameters, procedure time, ablation time, ablation points and fluoroscopy time. RESULTS A bidirectional block of the CTI was achieved in all patients. Patients with severe PAH had a significantly longer procedure time (78±40 min vs. 62±29 min; p=0.033), total ablation time (20±11 min vs. 15±9 min; p=0.02) and more ablation lesions (26±16 vs. 19±12; p=0.018) as compared to patients without PAH. CONCLUSION Cavotricuspid isthmus dependent flutter ablation in patients with PAH is associated with longer procedure duration and a greater amount of cumulative tissue ablation needed to achieve bidirectional block of the CTI compared to patients without pulmonary hypertension.

Left ventricular assist improves autonomic imbalance in patients with persistent myocardial dysfunction.

Background Left ventricular assist devices (LVAD) are an effective therapeutic option for end-stage heart failure (HF). Reduced heart rate variability (HRV) as a result of autonomic derangement is evident in chronic heart failure and several studies have established the independent prognostic value of HRV in chronic heart failure. Objective In the present study we investigated whether autonomic function is restored in patients after LVAD implantation with persistent, severely depressed left ventricular function. Methods Ambulatory Holter ECG recordings were collected in heart failure patients with an LVAD (n=8) und age-matched heart failure patients without an LVAD (n=7) both on optimal medical therapy. Cardiac dimensions and function were assessed by echocardiography or angiography. Results Analysis for heart rate variability revealed reduced SDNN (67±4ms), SDANN (56±4ms) and triangular index (18±1) in heart failure patients on optimal medical therapy. However patients with LVAD demonstrated a restoration in heart rate variability with normal SDNN (108±9ms), SDANN (103±8ms) and triangular index (29±2). Compared to patients without LVAD this difference was statistically significant (p<0.01). Conclusions In end-stage heart failure patients autonomic imbalance indicated by severely reduced heart rate variability is restored after LVAD implantation with unloading of the failing heart.

A prospective experience with the lead integrity alert: new certainties and new uncertainties.

Lead fracture is one of the major complications in implantable cardioverter defibrillator (ICD) therapy often leading to a series of inadequate shocks and thus greatly impairing quality of life of patients. The novel lead integrity alert algorithm by Medtronic (Medtronic Inc., Minneapolis, MN, USA) is addressing this problem. We report a case of a lead failure being correctly predicted by shifting lead impedances about 4 weeks before the first episode of oversensing. Additionally, our case illustrates the new problem of how to clinically handle a patient with a highly probable, but not completely certain, ICD-lead failure.