J CLIN PSYCHIATRY 43 4
April 1982
JOAN P GERRING. M.D. and HELEN M SHIELDS. M D

Abstract

The authors describe the cardiovascular complications of ECT in 42 patients undergoing this procedure during a one year period at a psychiatric referral center. Twenty-eight percent of the entire group of patients developed ischemic and/or arrhythmic complications following ECT. Seventy percent of the patients who had a history, physical or EKG evidence of cardiac disease developed cardiac complications. On the basis of this data, a high risk category for ECT is defined more precisely than previously. Recommendations are made for managing this high risk category of depressed patients In order to treat them with maximum safety and effectiveness. (J Clin Psychiatry 43:140-143. 1982)

A mortality rate of less than 1% has been consistently reported for patients undergoing electroconvulsive therapy (ECT), the most common side effect being memory impairment. Fortunately this is usually a short term loss which may be minimized with the use of unilateral ECT. With the addition of a muscle relaxant to modify ECT, fractures are no longer the second most common complication. Rather cardiovascular complications have taken this place. In this study we define a psychiatric population with high medical risk to develop cardiovascular complications of varying severity. We emphasize the identification and special care of this group.

Method

The charts of the 42 patients who had undergone a course of electroconvulsive therapy at Payne Whitney Clinic (PWC) during the period July 1, 1975 to July 1, 1976 were reviewed. Five patients had undergone two separate courses of ECT during this time period.

During the year July 1975 to July 1976, 924 patients were admitted to PWC. There were 347 males and 577 females: 42 patients or 4.5% received ECT. The average age of the ten men receiving ECT was 51 years and the average age of the 32 women receiving ECT was 54.7 years. Thirty-three patients (78%) of the group were diagnosed as having an affective disorder. These patients had an average age of 59.4 years and received an average of seven treatments. Seven patients (16%) were diagnosed as schizophrenic. These patients were much younger on the average than the preceding group (29.4 years) and had twice as many treatments per patient.

Seventeen of our patients (40%) presented with cardiac disease. This group included all patients with a history of angina, myocardial infarction, congestive heart failure, abnormal electrocardiogram, hypertension. (Table l)

The standard preparation for ECT during the year July 1, 1975 to July 1, 1976 consisted of a physical examination, hematocrit, hemoglobin and white count, urinalysis, chest x-ray, skull x-ray, lateral spine x-rays, electrocardiogram and electroencephalogram. Medical clearance, if any value was abnormal or the history revealed significant medical problems, was obtained from an internist, cardiologist, or neurologist.

Psychotropic medications were discontinued on the day prior to the first treatment and the patient was fasted overnight. One-half hour prior to a treatment 0.6 mg atropine sulfate was injected intramuscularly. First and second year psychiatric residents were in attendance in the ECT suite. After application of electrodes, the patient was anesthetized with intravenous thiopental, with a mean amount of 155 mg and a range of 100 to 500 mg. Intravenous succinylcholine, with a mean of 44 mg and a range of 40 to 120 mg was used for muscle relaxation. Mask ventilation with 100% oxygen was then begun continuing until the point in treatment when the effects of the succinylcholine were wearing off and the patient could resume breathing without assistance. This usually occurred about five to ten minutes after the dose. Patients with pulmonary disease were to have a baseline set of blood gases, carbon dioxide retainers not being hyperventilated. The modified grand mal convulsion was induced by an electric current that varied from l30 to 170 volts given over a period of 0.4 to 1 second (Medcraft Unit Model 324). In ten of 17 patients with history, physical or EKG evidence of cardiovascular disease, a cardiac monitor or twelve lead EKG machine was used to monitor their rhythm immediately before, during and for a 10-15 minute period following an ECT treatment.

The average systolic blood pressure on admission in the group who did not experience cardiovascular complications was 129 ± 21 mm Hg. The average of the highest systolic blood pressures recorded after the first ECT in this group was 173 ± 40mm Hg. A multivariate analysis was performed on the baseline blood pressure for each patient as recorded on his/her initial physical examination, as well as the highest blood pressure noted after each of the first four ECT treatments (unless the patient had less than four treatments). The systolic and diastolic pressure rise after each of the treatments were separately compared to the baseline blood pressure.

The treatment course for depression consisted of from five to 12 treatments given as three treatments per week. For the treatment of schizophrenic illness, the treatment plan consisted of five treatments per week to a total of 15 to 20 treatments.

Results

During July 1, 1975 to July 1, 1976. 12 of the 42 patients (28%) who underwent modified ECT at the New York Hospital developed an arrhythmia or ischemia following the procedure. In patients with known cardiac disease, the complication rate rose to 70%. This rate may have been even higher had all 17 cardiac patients been monitored. The four cardiac patients with no complications were not monitored so arrhythmias could easily have been missed. The 12 patients who developed cardiac complications of ECT came entirely front this group of 17 cardiac patients (Table 1) with known cardiovascular disease prior to ECT. Six of the cardiac patients had a history of hypertension, four had rheumatic heart disease, four had ischemic heart disease and three had arrhythmias or a history of arrhythmias. Sixteen of the 17 patients had an abnormal electrocardiogram prior to ECT: these included three who had a definite old myocardial infarction, two who had a possible old myocardial infarction, three other patients who had a bundle branch block, four patients with arrhythmias and four others with either left ventricular hypertrophy, left atrial abnormality or first degree heart block. Thirteen of the 17 patients were on a digitalis preparation, six were on diuretics and six were on an antiarrhythmic spent.