Resuscitation training for cardiac patients and their relatives--its effect on anxiety.

It is feared by many doctors that teaching basic life support (BLS) to high risk cardiac patients or a member of the family increases their anxiety. We trained a group of patients with recurrent ventricular tachycardia in BLS together with a friend or family member. Measurement of anxiety before and three months after training demonstrated a reduction in anxiety in both groups. This suggests that basic life support training can be targeted to high risk groups without fear of increasing anxiety.     

Rapid autonomic tone regulation of atrioventricular nodal conduction in man

The changes in P-P intervals and atrioventricular nodal (AVN) conduction during the Valsalva maneuver were studied in 17 patients. In spite of a significant decrease in the sinus P-P interval during phase II of the maneuver (733 +/- 143 to 520 +/- 86 msec, p less than 0.005) and prolongation during phase IV (884 +/- 171 msec, p less than 0.01), there was no change in the AH interval (control: 78 +/- 15: phase II: 76 +/- 15: phase IV: 72 +/- 14 msec, N.S.). In six patients consecutive P-P intervals during phase II were recorded in solid-state memory and were used to trigger pacing of the high right atrium at rest. This showed a significant increase in the AH interval (75 +/- 10 to 123 +/- 45 msec, p less than 0.05). Valsalva maneuver during constant rate atrial pacing resulted in a significant decrease in the AH interval during phase II (115 +/- 36 to 80 +/- 15 msec, p less than 0.001). During phase IV there was prolongation of the AH interval (156 +/- 58 msec) but in 11 patients (61%) a variable degree of Wenckebach periodicity appeared. Thus autonomic tone modulates the changes in AVN conduction induced during physiologic heart rate variation, resulting in maintenance of adequate 1:1 AVN conduction.     

Survey of the attitudes of British physicians to pacing.

OBJECTIVES--To assess how the opinions of cardiologists, physicians, and general practitioners on the indications for permanent pacing compare with published guidelines, and to determine whether resources, pacing experience, and position influence referral practices. DESIGN--Anonymous postal survey by questionnaire from St Bartholomew's Hospital, London and the King's Fund Institute, London. The questionnaire established the respondent's position, resources, and previous pacing experience. Eleven clinical and electrocardiographic situations were described and respondents were asked to decide on whether pacing was indicated. The responses received were compared with the guidelines provided by the 1984 American College of Cardiology/American Heart Association task force. PARTICIPANTS--The 630 members of the British Cardiac Society, 1370 randomly selected general physicians, and 2000 general practitioners. RESULTS--Patients with symptoms were more likely to be referred for pacing than symptom free patients regardless of underlying aetiology. In relatively symptom free patients the frequency with which pacing was recommended was low, even when it was unequivocally indicated on prognostic grounds. Failure to recommend pacing was unrelated to diagnostic facilities or referral difficulties. Respondents with pacing experience were more likely to recommend pacing. CONCLUSIONS--The physicians surveyed had a conservative approach towards recommending pacing. Most physicians were influenced predominantly by symptoms and the prognostic indications for pacing were not well appreciated.     

Exercise induced vasodepressor syncope.

Five cases of exercise induced pure vasodepressor syncope in patients without significant structural heart disease are reported. Hypotension and symptoms of syncope or pre-syncope were induced by treadmill exercise testing and in each case limited exercise performance. Evidence of inappropriate peripheral vasodilation, probably as a consequence of ventricular mechanoreceptor stimulation, was shown in all five patients. Head up tilt testing resulted in hypotension in four patients and isoprenaline infusion in the supine position resulted in hypotension in the fifth. These patients had a new condition of exercise induced neurally mediated (vasodepressor) syncope without appreciable structural cardiac abnormalities.     

Recurrence of left atrium-pulmonary vein conduction following successful disconnection in asymptomatic patients.

BACKGROUND: The clinical significance of conduction recurrences in isolated pulmonary veins of patients with atrial fibrillation is not established. METHODS: Twenty-two patients with paoxysmal atrial fibrillation underwent successful pulmonary vein isolation. Six months after the procedure, 14 patients were free of atrial fibrillation. Two of these patients were subjected to repeat mapping of the left superior pulmonary vein. RESULTS: There was recurrence of pulmonary vein to left atrium conduction despite complete lack of symptoms or evidence of recurrent atrial fibrillation. CONCLUSION: Successful pulmonary vein isolation with abolition of paroxysmal atrial fibrillation does not confer permanent disconnection of the pulmonary vein musculature from the left atrium.     

Catheter ablation by low energy DC shocks for successful management of atrial flutter.

OBJECTIVE--To assess the effects of low energy ablation of the substrate for atrial flutter. DESIGN--Initial retrospective analysis of patients undergoing low energy ablation of the atrioventricular node for refractory atrial flutter (group 1) was followed by a prospective assessment of low energy ablation in the posterio-inferior right atrium for the same condition (group 2). SETTING--Tertiary referral centre for management of cardiac arrhythmias. PATIENTS--Seven men (aged 50-67 years) with refractory atrial flutter. INTERVENTIONS--Multiple (3-10) low energy DC shocks with a cumulative energy of 100-245 J in the region of the atrioventricular node in group 1 and 12-15 low energy DC shocks (cumulative energy 110-235 J) guided by the anatomical landmarks of the triangle of Koch and applied directly to the atrial wall. MAIN OUTCOME MEASURE--Freedom from recurrence of atrial flutter. RESULTS--In group 1 despite initial complete atrioventricular block in three patients, atrioventricular conduction had resumed in all by one month. All four, however, were in sinus rhythm at follow up six to 13 months later. Two of the three patients in group 2 were free of atrial flutter at follow up three to four months after ablation. CONCLUSION--Ablation of the atrial flutter substrate with low energy DC shocks is feasible. Precise electrophysiological mapping is not necessary.     

Management of ventricular arrhythmias associated with mitral valve prolapse by combined alpha and beta blockade

Ventricular arrhythmias are common in patients with mitral valve prolapse. Ten patients with echocardiographically confirmed mitral valve prolapse and documented ventricular arrhythmias were included in this study. The aim was to assess the value of combined alpha- and beta-blockade (labetalol) compared with beta-blockade alone (propranolol) in the management of ventricular arrhythmias in these patients. The study was performed using physiological stress, such as the Valsalva manoeuvre, isometric exercise and treadmill exercise, to initiate ventricular arrhythmias before and after intravenous propranolol or labetalol and to document arrhythmias during 24 hour electrocardiography before and after oral medication. Labetalol and propranolol decreased the heart rate and blood pressure response to these manoeuvres to a similar extent but labetalol was more effective in the control of the ventricular arrhythmias. These findings suggest that alpha adrenergic receptors may play a role in the pathogenesis of the ventricular arrhythmias in mitral valve prolapse syndrome and that labetalol offers an alternative treatment for the management of this condition.