VENTRICULAR FIBRILLATION DURING SELECTIVE ANGIOCARDIOGRAPHY

The hazard of electrocution during patient monitoring

The ever-present hazard in patient monitoring is electrocution resulting in ventricular fibrillation. Fire and explosion hazards are possibilities but seem to be very remote.

Iatrogenic electrocution can occur when:

(a) more than one piece of electrical equipment is connected to the patient.

(b) the distal end of an intracardiac electrode is handled.

(c) pericardiocentesis is carried out with ECG monitoring,

Under these circumstances, small currents, of the order of 100-200 μA, may cause ventricular fibrillation. There is evidence that the ventricular fibrillation threshold is substantially lowered by anoxia and acidosis but it seems to be unaffected by barbiturate anaesthesia.

This paper suggests that the physician or surgeon should understand the risks but may need the expert advice of an electrical engineer. Ventricular fibrillation which has occurred under these circumstances requires careful, expert investigation to establish whether or not it was electrically induced.

Complications of left heart anoaphy. A study of 1,000 consecutive cases

A study of 1,000 consecutive left heart cineangiocardiograms was made to determine the frequency of various complications. Ten per cent of angiographic procedures caused minor complications such as nausea, vomiting, transient arrhythmias, loss of pulse, or hives. Most of these complications were gone before the patient left the cardiac catheterization laboratory.

Major problems were associated with 3.1% of the angiograms performed. The majority involved either vessel thrombosis (1.2%) or cardiac complications such as arrhythmias, intramyocardial dye injection, or myocardial infarcts (1.4%). Femoral arterial thrombosis was especially frequent in patients with mitral valve disease and low cardiac index. The use of lidocaine-lubricated catheters, tape traction hemostasis, and Fogerty catheter clot removal virtually eliminated brachial arterial thromboses. This route is now used almost exclusively for left heart angiography at our institution.

Most cardiac complications resulted from open-end catheter angiography, especially through transseptal catheters. The frequency of major cardiac complications has decreased markedly since the regular use of closed-tip catheters via the brachial artery route was begun for left heart angiography.