Idiopathic left ventricular tachycardia in children.

BACKGROUND: Idiopathic left ventricular tachycardia (ILVT) is a rare but well-recognized clinical entity. The clinical characteristics and prognosis of this form of ventricular tachycardia (VT) in Thai children is not known. OBJECTIVE: To define clinical presentations, drug therapies, roles of radiofrequency (RF) catheter ablation, and the short-term outcome of these children in Thailand. PATIENTS AND METHOD: From April 1999 to June 2007, 10 patients were diagnosed as ILVT by specific electrocardiographic features and therapeutic response. All patients had a structurally normal heart. Data were collected retrospectively. Baseline clinical information, 12-lead electrocardiography (ECG) during VT, responses to drug therapy, results of RF catheter ablation therapy, and outcome were determined. RESULTS: Median age at presentation was 9.5 years (range, 3.8 to 14.0 years). Three patients (30%) were male. Eight patients (80%) were diagnosed as supraventricular tachycardia (SVT) before ILVT diagnosis. Median duration from SVT diagnosis to the correct diagnosis was 1.5 years (range, 0 to 6.0 years). Palpitation and chest pain were usual clinical manifestations while congestive heart failure was the presentation in one due to incessant tachycardia. Two patients had recurrent VT episodes during acute febrile illnesses. The majority of patients responded to intravenous verapamil. RF catheter ablation was performed in 3 patients with recurrence of the VT in one. CONCLUSION: Prompt recognition of the ILVTespecially in the emergency department is very important. Verapamil is effective for acute termination as well as prevention of VT recurrence. When VT is refractory to medical therapy, RF catheter ablation is safe and effective. The short-term prognosis was good.

Feasibility, safety, and mid-term efficacy of cardiac resynchronization therapy in patients with severe heart failure and ventricular conduction delay: Chulalongkorn experience.

BACKGROUND: Heart failure is a major and growing public health problem in developed and developing countries. Despite major advances in medical therapy, morbidity and mortality remain high. Cardiac resynchronization therapy (CRT) has been proposed as an adjunctive therapy in patients with drug-refractory heart failure and ventricular conduction delay. Short and long-term studies have demonstrated the clinical benefits of CRT. OBJECTIVE: The present study was designed to assess the feasibility, safety, and mid-term efficacy of CRT in patients with severe heart failure and ventricular conduction delay in the institute. MATERIAL AND METHOD: Ten patients with severe heart failure in New York Heart Association (NYHA) functional class III or IV with left ventricular ejection fraction (LVEF) < 35%, QRS duration >120 ms with left bundle branch block morphology received CRT At baseline, and 6 months after implantation, the following parameters were evaluated: NYHA class, QRS duration, LVEF N-terminal pro-brain natriuretic peptide (NT-pro BNP) level, 6-minute walking distance, SF-36 quality-of-life (QOL) score, and number of heart failure visit. RESULTS: All clinical parameters improved significantly at 6 months. NYHA class decreased from 3.5 +/- 0.5 to 2.4 +/- 0.7 (p < 0.01). QRS duration decreased from 145 +/- 22 ms to 126 + 6 ms (p < 0.01). LVEF increasedfrom 21 +/- 6% to 31 +/- 12% (p < 0.01). NT-pro BNP level decreased from 2503 +/- 1953 pg/ml to 767 +/- 342 pg/ml (p < 0.01). The 6-minute walking distance increased from 153 +/- 122 m to 278 +/- 128 m (p < 0.01). QOL score improved from 66 +/- 14 to 98 +/- 25 (p < 0. 01). The number of heart failure visits was reduced from 3.8 +/- 3.7 per year to 0.5 +/- 0.8 visit per year (p < 0.01). Seventy percent of patients were free of heart failure visit for one year after implantation. One patient had sudden cardiac death eleven months after implantation. There was no procedure-related mortality. One patient had left ventricular lead dislodgement 3 months after implantation. CONCLUSION: In the present study, CRT was safe and effective in improving heart failure symptom, functional status, LV function, and quality of life. CRT also reduced heart failure hospitalization in the presented severe heart failure and ventricular conduction delay patients.