Right ventricular lead induced ventricular arrhythmia-A rare complication of cardiac resynchronization therapy.

BACKGROUND: A 53-year-old male with heart failure secondary to anterior wall myocardial infarction treated with cardiac resynchronization-defibrillator (CRT-D) device presented with ventricular arrhythmia: repetitive incessant slow ventricular tachycardias (VT) below the CRT-D detection zone, accelerated ventricular rhythm, and numerous premature ventricular ectopic beats (ExV), resulting in loss of biventricular pacing. METHODS AND RESULTS: Nonsustained monomorphic VT (nsVT) and ExV were observed in an electrocardiogram under biventricular stimulation. During noninvasive CRT-D programming, ventricular bigeminy reproducibly recurred only at right ventricular (RV) pacing and its morphology was almost identical to the stimulated beats. The left ventricular (LV) pacing failed to induce ventricular ectopy or tachycardia. CONCLUSIONS: This unusual case shows a rare phenomenon of late proarrhythmic effect due to the RV lead pacing-a new finding reported only in a few publications. Here we present our approach to CRT programming that suppressed the clinical arrhythmia without the need of catheter ablation and achieving the high biventricular pacing capture rate along with optimal hemodynamic CRT-D performance.

Conscious sedation during cryoballoon ablation of atrial fibrillation: a feasibility and safety study.

BACKGROUND: Cryoballoon ablation for atrial fibrillation (cryoAF) is relatively simple, cost-effective and easy procedure. However, general anesthesia during this procedure may have negative impact on patients' mortality and morbidity, as well as procedure costs. We sought to assess the feasibility and safety of conscious sedation during cryoAF. METHODS: Patients with paroxysmal or persistent, drug-refractory AF who underwent a first procedure of cryoAF were included in our single-center, retrospective study. The loading dose of midazolam was 2 mg and loading fentanyl dose was 25 µg intravenously. Additional doses of midazolam and fentanyl were administered, if necessary. Midazolam and fentanyl were administered to maintain amnesia and analgesia, and patients' responsiveness in Ramsay Sedation Score was assessed every 10 minutes with sedation kept at the Ramsey Sedation Scale not exceeding Ramsey 3 Grade. RESULTS: A total of 71 patients with mean age 59.5±11.1 years were enrolled (48 males, 68%). The TEE and the TEE-guided transseptal puncture was feasible in all patients. The mean duration of cryoAF procedure was 136.3±36.0 minutes. The overall mean midazolam and fentanyl used doses were: 5.1±3.1 mg (55.7±35.1 µg/kg) and 98.9±51.1 µg (1.13±0.60 µg/kg). In 3 patients (4.2%), vascular complications occurred (femoral vein bleeding with hematoma formation without communication with femoral artery). In 1 case (1.4%) transient right phrenic palsy was observed; symptoms disappeared completely within 12 hours after procedure. The overall acute procedural success rate of cryoAF (defined as electrical isolation of all pulmonary veins) was 68/71 (95.8%). CONCLUSIONS: Conscious sedation is a safe, efficacious and feasible during cryoablation of pulmonary veins for AF.

Outcomes of percutaneous coronary intervention in patients after previous coronary artery bypass surgery.

BACKGROUND: Patients after previous coronary artery bypass grafting (CABG) often require repeat percutaneous revascularisation due to poor patency rates of saphenous vein grafts (SVG) and higher risk of re-CABG. Few data are available to evaluate different percutaneous revascularisation strategies in patients after previous CABG. AIM: To evaluate outcomes of percutaneous coronary intervention (PCI) in patients after previous CABG, including the effect of treatment on the quality of life and symptoms, and secondly to assess the relation between angiographic factors and treatment outcomes METHODS: This was a prospective observational study which included 78 patients after previous CABG. Following coronary angiography, the patients were assigned to one of three groups: group A (n = 20), PCI of a SVG (PCI SVG); group B (n = 29), PCI of a native coronary artery (PCI NA); group C (n = 29), control group that received medical treatment (MT) only. Duration of follow-up was 12 months. RESULTS: Compared to MT patients, patients treated with PCI had significantly higher Canadian Cardiovascular Society (CCS) class (2.75 vs. 2.41, p = 0.03) and more frequently had coronary angiography performed due to unstable angina (57% vs. 31%, p = 0.04). Patients in the PCI SVG group had significantly older SVG conduits compared to the PCI NA group (13.4 years vs. 8.2 years, p = 0.005). At 12 months of follow-up, we found a significant improvement in the EQ-5D index of the quality of life, and a significant reduction in CCS class in the PCI SVG group (0.66 vs. 0.7, p = 0.0003, and 2.75 vs. 1.9, p < 0.001, respectively) and in the PCI NA group (0.65 vs. 0.72, p < 0.001, and 2.75 vs. 2.17, p < 0.001, respectively), but no improvement in the MT group. Treatment outcomes did not differ significantly between the three groups (combined endpoint rate 20% vs. 13% vs. 27.5%, p = 0.37). In multivariate analysis, SVG age > 11 years was identified as a significant predictor of poor outcomes in patients treated with PCI after previous CABG. CONCLUSIONS: PCI in patients after previous CABG does not improve prognosis but significantly improves the quality of life and reduces symptom severity.