The establishment of a local permanent pacemaker service in a district general hospital increased the pacemaker implantation rate from 22 per million population per year to 152 per million population per year over the first 6 years of the service. Forty eight per cent of patients were referred by general practitioners and 52% by hospital specialists. Single chamber demand pacing (VVI) was used ...

Abstract Aims Cardiac dyssynchrony in patients with repaired Tetralogy of Fallot (rToF) has been attributed to right bundle branch block (RBBB), fibrosis and/or the patches that are inserted during repair surgery. We aimed investigate basis abnormal activation rToF by mapping electrical sequence sinus rhythm (SR) and ventricular (RV) pacing. Methods Results A total 17 were studied [13 rToF, 2 l...

We determined the effect of heart rate on the disposition of neurally released norepinephrine from the cardiac tissues in open-chest, anesthetized dogs with complete atrioventricular block. After injecting desipramine to block the neuronal uptake of norepinephrine, we stimulated the cardiac sympathetic nerves supramaximally for about 3 minutes at a mean frequency of 2.7 Hz. In one series of exp...

T he concept of twofers is widely used in a variety of situations and applications ranging from cabling devices in theatrical stage lighting to Broadway tickets to 2 hamburgers for a quarter at Tucker’s Twofers to items of merchandise to something that “satisfies 2 criteria or needs simultaneously.” The paper by Petronio et al. (1), in this issue of JACC: Cardiovascular Interventions, takes thi...

6 List of original papers 7 List of abbreviations 8 Introduction 9 Cardiac cellular electrophysiology 12 Recording cardiac electricity 16 Electrocardiography (ECG) 16 Vectorcardiography (VCG) 16 Pacemaker treatment 20 Sick Sinus Syndrome 21 Hypertrophic Obstructive Cardiomyopathy (HOCM) 21 Wolff-Parkinson-White Syndrome (WPW syndrome) 22 Aims 23 Material and Methods 24 Studies I and II 24 Study...

The purpose of this study was to determine if hypertrophied myocardium was associated with diminished cardiac function, restricted oxygen supply, or oxygen consumption during tachycardia. Myocardial oxygen supply and oxygen consumption were determined during baseline and atrial pacing conditions 30 days after New Zealand White rabbits were prepared as one-kidney, one clip Goldblatt hypertensive...

BACKGROUND Right ventricular (RV) pacing generates regional disparities in electrical activation and mechanical function (ventricular dyssynchrony). In contrast, left ventricular (LV) or biventricular (BIV) pacing can improve cardiac efficiency in the setting of ventricular dyssynchrony, constituting the rationale for cardiac resynchronization therapy (CRT). Animal models of ventricular dyssync...

The reproducibility of clinical and hemodynamic events during two successive pacing periods separated by a 20-minute interval was evaluated in 33 patients with stable angina pectoris. Continuous pacing with stepwise increase in pacing rate was assessed in 19 patients and discontinuous pacing in which pacing was temporarily interrupted at each rate was evaluated in the other 14 patients. During ...

Neurally-mediated syncope has a broad clinical spectrum which ranges from typical vasovagal syncope on one hand, to those situations in which reflex syncope occurs with uncertain, or even apparently absent, triggers or prodromes, on the other hand. Overlap of clinical features is frequent in clinical practice and makes any classification difficult to apply when selecting patients for cardiac pa...

BACKGROUND Cardiac resynchronization therapy has emerged as an important therapy for advanced systolic heart failure. Among available cardiac resynchronization therapy pacing modes that restore ventricular synchrony, it is uncertain whether simultaneous biventricular (BiV), sequential BiV, or left ventricular (LV) pacing is superior. The Device Evaluation of CONTAK RENEWAL 2 and EASYTRAK 2: Ass...