Undersensing of demand pacemakers in acute myocardial infarction

Indications for and complications of temporary transvenous cardiac pacing

A prospective survey was conducted of the indications for and complications of 153 temporary transvenous cardiac pacing lead insertions in 148 patients. Pacing for bradyarrhythmias or potential bradyarrhythmias (Group I) accounted for 105 insertions, wide complex tachycardia (Group II) 17, and narrow complex tachycardia (Group III) 31 pacing electrode insertions respectively. The infraclavicular subclavian vein approach was used in 73%. The median insertion time was 20 minutes. Group I: 77% were undertaken because of severe symptoms. On 64 occasions (61%) the patient had complete heart block or ventricular asystole. Group II: The lead was inserted to treat and often assist in the diagnosis of the wide complex tachycardia. Ventricular 'burst' pacing reverted ventricular tachycardia in 13 (76%). Group III: Rapid atrial 'burst' pacing was used to treat supraventricular tachyarrhythmias (paroxysmal supraventricular tachycardia and atrial flutter) resistant to medical therapy. Pacing was successful in reverting 28 (90%). A complication occurred in 27 (18%) of 153 lead insertions, 11 (7%) were serious. No complication resulted in the death of a patient. Temporary transvenous pacing is safe and effective for the treatment of bradyarrhythmias and certain tachyarrhythmias.

Cardiac pacing in intensive care

Cardiac pacing techniques and equipment have developed dramatically in recent years. Bradycardias and tachycardias may be effectively treated by pacing. Bradyarrhythmias: It is generally accepted that pacing is indicated for a sustained symptomatic bradycardia. Prophylactic pacing for 'high-risk' bundle branch block in acute myocardial infarction is more controversial. A new era in cardiology has been introduced with the advent of 'physiological pacing', i.e. pacing of the heart with the maintenance of atrioventricular synchrony and varying the heart rate according to the body's metabolic leads. Modern pacing systems, which allow the atria and ventricles to contract in sequence, improve cardiac haemodynamics, result in subjective improvement and increase exercise tolerance. There are, however, pacemaker-associated and pacemaker-mediated tachyarrhythmias. Further advances in technology should overcome these problems. Tachyarrhythmias: Intracardiac electrocardiograms are often useful in the diagnosis of tachyarrhythmias, especially wide complex tachycardias. Rapid pacing of the atria in certain supraventricular tachycardias or of the ventricle in ventricular tachycardia is an alternative to cardioversion in many instances. This form of treatment is usually utilised in conjunction with drug therapy.