Catheter Ablation ; Electrocardiography ; Heart Ventricles ; Humans ; Tachycardia, Ventricular ; therapy

Ventricular premature complexes (VPCs) are known to be one of the most benign cardiac arrhythmias when they occur in structurally normal hearts. We experienced a 32-year old man who presented with dyspnea, palpitations and very frequent VPCs (31% of the total heart beats). Echocardiography revealed a dilated left ventricle (LV 66 mm at end-diastole and 57 mm at end-systole) and a decreased ejection fraction (34%). Very frequent VPCs had been detected 10 years previously and he underwent a failed radiofrequency catheter ablation (RFCA) procedure at that time. The patient had been treated with heart failure medications including betablockers, ACE inhibitors and spironolactone for the two most recent years. Six months after we eliminated these VPCs with a second RFCA procedure, the heart returned to normal function and size. Long standing and very frequent VPCs could be the cause of left ventricular dysfunction in a subset of patients who suffer with dilated cardiomyopathy, and RFCA should be the choice of therapy for these patients.
Ventricular Premature Complexes/*complications ; Tachycardia, Ventricular/*etiology/therapy ; Male ; Humans ; *Catheter Ablation ; Cardiomyopathies/*etiology/therapy ; Adult

Electrical defibrillation is the most effective way to treat the ventricular tachycardia (VT) and ventricular fibrillation (VF). An automatic external defibrillator based on DSP is introduced in this paper. The whole design consists of the signal collection module, the microprocessor controlingl module, the display module, the defibrillation module and the automatic recognition algorithm for VF and non VF, etc. This automatic external defibrillator has achieved goals such as ECG signal real-time acquisition, ECG wave synchronous display, data delivering to U disk and automatic defibrillate when shockable rhythm appears, etc.
Algorithms ; Defibrillators ; Equipment Design ; Humans ; Tachycardia, Ventricular ; therapy ; Ventricular Fibrillation ; therapy

BACKGROUNDCardiac resynchronization therapy (CRT) could improve heart function, symptom status, quality of life and reduce hospitalization and mortality in patients with severe heart failure (HF) with optimal medical management. However, the possible adverse effects of CRT are often ignored by clinicians.

METHODA retrospective analysis of CRT over a 6-year period was made in a single cardiac center.

RESULTSFifty-four patients were treated with CRT(D) device, aged (57 ± 11) years, with left ventricular ejection fraction of (32.1 ± 9.8)%, of which 4 (7%) developed ventricular tachycardia/ventricular fibrillation (VT/VF) or junctional tachycardia after operation. Except for one with frequent ventricular premature beat before operation, the others had no previous history of ventricular arrhythmia. Of the 4 patients, 3 had dilated cardiomyopathy and 1 had ischemic cardiomyopathy, and tachycardia occurred within 3 days after operation. Sustained, refractory VT and subsequent VF occurred in one patient, frequent nonsustained VT in two patients and nonparoxysmal atrioventricular junctional tachycardia in one patient. VT was managed by amiodarone in two patients, amiodarone together with beta-blocker in one patient, and junctional tachycardia was terminated by overdrive pacing. During over 12-month follow-up, except for one patient's death due to refractory heart and respiratory failure in hospital, the others remain alive and arrhythmia-free.

CONCLUSIONSNew-onset VT/VF or junctional tachycardia may occur in a minority of patients with or without prior history of tachycardia after biventricular pacing. Arrhythmia can be managed by conventional therapy, but may require temporary discontinuation of pacing. More observational studies should be performed to determine the potential proarrhythmic effect of CRT.

Anti-Arrhythmia Agents ; therapeutic use ; Child ; Humans ; Tachycardia, Atrioventricular Nodal Reentry ; drug therapy ; Tachycardia, Ectopic Atrial ; drug therapy ; Tachycardia, Ectopic Junctional ; drug therapy ; Tachycardia, Supraventricular ; drug therapy ; Tachycardia, Ventricular ; drug therapy

Aged ; Catheter Ablation ; Defibrillators, Implantable ; Electrocardiography ; Humans ; Infarction ; therapy ; Male ; Tachycardia, Ventricular ; therapy

Animals ; Cardiac Resynchronization Therapy ; adverse effects ; Dogs ; Heart Failure ; therapy ; Tachycardia, Ventricular ; etiology

Non-typhoidal salmonella is rarely the cause of pacemaker infection. A 68-year-old man was referred to our hospital with tenderness and swelling at his cardiac resynchronization therapy defibrillator (CRT-D) implantation site. He had undergone CRT-D implantation because of sustained ventricular tachycardia and heart failure 7 years earlier, and the generator had been changed 2 months earlier. Twenty-four years earlier, he had undergone aortic valve replacement and mitral valve repair. We removed the generator and all of the CRT-D leads. After lead extraction, non-typhoidal salmonella serogroup B was cultured at the pocket and lead tip. The patient was managed successfully with lead extraction and antibiotic therapy.
Aortic Valve ; Cardiac Resynchronization Therapy ; Defibrillators ; Heart Failure ; Humans ; Mitral Valve ; Salmonella ; Salmonella Infections ; Tachycardia, Ventricular

Arrhythmias, Cardiac ; Catheter Ablation ; Electrocardiography ; Extracorporeal Membrane Oxygenation ; Humans ; Tachycardia, Ventricular/therapy*

Defibrillators, Implantable ; Humans ; Ryanodine Receptor Calcium Release Channel ; Tachycardia, Ventricular/therapy*