Echocardiographic evaluation of patients with undocumented arrhythmias occurring in adults late after repair of tetralogy of Fallot.

AIMS: Arrhythmias occurring late after repair of tetralogy of Fallot (ToF) are common. Due to the risk of sudden cardiac death, attention is focused towards ventricular tachycardias (VT). The aims of this study were to determine the clinical profile of patients with known benign and malignant arrhythmias and to assess patients with palpitations without documented arrhythmias. METHODS AND RESULTS: Fifty-two patients with prior ToF repair were included in this study (mean follow-up: 18+/-7.3 years). Echocardiographic measurements such as left ventricular ejection fraction, left and right atrial (LA and RA) diameters, left and right ventricular diameters (LVEDD and RVEDD), pulmonary and tricuspid regurgitation (TI and PI) and electrocardiographic parameters such as QRS duration, P-wave duration, P-wave dispersion were obtained and compared in patients with and without a history of palpitations. The same comparisons were performed between patients with documented supraventricular tachycardias (SVT) and VT. Twenty-seven of 52 patients had a clinical history of palpitations. The remaining 25 patients served as controls. Eleven patients had documented SVT and 6 patients had documented VT. In patients with documented SVT, the RA size and the QRS durations were significantly higher than in the controls (RA: 55.3+/-5.6 vs. 47.4+/-4.8 mm, P=0.03, QRS: 160.0+/-25.9 vs. 131.8+/-26.1 ms, P=0.01). In patients with VT, the LVEDD, LA, and QRS durations showed significantly higher values compared with the control patients (LVEDD: 53.5+/-4.7 vs. 45.6+/-6.8 mm; LA: 56.0+/-3.4 vs. 48.5+/-4.8 mm, P=0.01; QRS: 169.5+/-29.7 ms vs. 131.8+/-26.1 ms; P=0.001). The only significant differences between patients with and without palpitations were the RA size (58.2+/-3.9 vs. 50.5+/-5.2 mm, P=0.02) and the P-wave dispersion (26.8+/-15.2 vs. 16.6+/-4.3 ms, P=0.04). CONCLUSION: Our present data suggest that undocumented arrhythmias are most likely SVTs and are associated with increased RA size.

Vitamin D Deficiency Predicts Poor Clinical Outcomes in Heart Failure Patients Undergoing Cardiac Resynchronization Therapy.

BACKGROUND AND AIMS: Resynchronization therapy (CRT) improves mortality and induces reverse remodeling in heart failure (HF) patients with reduced ejection fraction and wide QRS. Nonetheless, some patients do not improve despite the optimal medical therapy and right indications for device implantation. Therefore, finding biomarkers suitable for identification of those patients is crucial. Vitamin D plays a classic hormonal role in the regulation of bone metabolism and also has physiological functions in wide range of nonskeletal tissues. Based on recent studies, low levels of vitamin D seem to directly contribute to pathogenesis and worsening of HF. We planned to assess the role of vitamin D levels on clinical outcomes of HF patients undergoing CRT. METHODS AND RESULTS: We enrolled 136 HF patients undergoing CRT. Total plasma vitamin D levels were measured at baseline and 6 months later. Primary endpoint was 5-year all-cause mortality; secondary endpoint was lack of good clinical response, defined as less than 15% increase of left ventricular ejection fraction after six months. During follow-up, 58 patients reached the primary, and 45 patients reached the secondary endpoint. Vitamin D levels less than 24.13 ng/mL predicted 5-year mortality (p = 0.045) and poor clinical response (p = 0.03) after adjusting to all significant baseline predictors. CONCLUSION: Our study showed that vitamin D deficiency has a significant impact in heart failure patients; it is an independent predictor of lack of midterm clinical response and long-term mortality in patients undergoing CRT. Therefore, monitoring vitamin D status of heart failure patients could be of clinical significance.

Transseptal Leftventricular Endocardial Pacing is an Alternative Technique in Cardiac Resynchronization Therapy. One Year Experience in a High Volume Center.

INTRODUCTION: In patients receiving cardiac resynchronization therapy (CRT), failure rate to implant the left ventricular (LV) lead by the traditional trans-venous approach is 4-8%. Surgical epicardial implantation is considered as an alternative, but this technique is not without morbidity. Evidence from case documentation and from small trial batches demonstrated the viability of endocardial LV lead implantation where surgical epicardial lead placement is not applicable. MATERIAL AND METHODS: Four patients were implanted with endocardial LV lead using the transseptal atrial approach after unsuccessful transvenous implantation. Implantation of an endocardial active fixation LV leads was successful in all patients with stable electrical parameters immediately after implantation and over the follow-up period. All patients received anticoagulation therapy in order to target the international normalized ratio of 2.5-3.5 and have not experienced any thromboembolic, hemorrhagic events, or infection. RESULTS: Follow-up echocardiography indicated significant improvement of LV systolic function (24 + 4.9 to 32 + 5.1 %, P = 0.023) with a notable improvement of the functional status. CONCLUSIONS: Endocardial left ventricular lead implantation can be a valuable and safe alternative technique to enable LV stimulation in high surgical risk patients where standard coronary sinus implant is unsuccessful.