Circuit weight training in cardiac patients.

This was a prospective, randomized evaluation of the safety and efficacy of 10 weeks of circuit weight training in patients, aged 35 to 70 years, with documented coronary artery disease. Circuit weight training refers to the performance of a series of weight-lifting exercises using a moderate load with frequent repetitions. Patients had participated in a supervised cardiac rehabilitation program for a minimum of 3 months before the study. Control patients (n = 20) continued with their regular exercise consisting of a walk/jog and volleyball program, while the experimental group (n = 20) substituted circuit weight training for volleyball. No sustained arrhythmias or cardiovascular problems occurred. The experimental group significantly increased treadmill time from 619 to 694 seconds while the treadmill time of the control group did not change. Strength in the experimental group increased by an average of 24% while there was no change in the control patients. Circuit weight training appears to be safe, and to result in significant increases in aerobic endurance and musculoskeletal strength compared with traditional exercise used in cardiac rehabilitation programs.

Routine serum enzyme tests in the diagnosis of acute myocardial infarction. Cost-effectiveness.

To determine the cost-effectiveness of routine use of serial SGOT, lactic dehydrogenase (LDH), and LDH isoenzyme determinations in patients with suspected acute myocardial infarction (AMI), 166 consecutive patients admitted to a coronary care unit were prospectively identified and clinical findings analyzed independently using predetermined criteria. Based on chest pain characteristics, ECG, and creatine kinase--MB (CK-MB) results, patients were placed in categories of definite AMI (31%), possible AMI (34%), or AMI excluded (36%). The SGOT and/or LDH patterns were considered positive (ie, suggestive of AMI) in 82% of the patients with definite AMI but only confirmed CK-MB results. Positive SGOT/LDH results yielded new clinically relevant information in only 14 patients (8%). Total charges for SGOT/LDH determinations in these 166 patients totaled $10,938 or approximately $780 for each additional clinically important positive result. When serial ECG and CK-MB results are available, routine serial SGOT/LDH determinations are not justified.

Routine preoperative exercise testing in patients undergoing major noncardiac surgery.

A prospective study of preoperative exercise testing was carried out in 200 patients older than 40 years scheduled for elective major noncardiac surgery under general anesthesia. The exercise test response was electrocardiographically positive in 32 patients (16%) (2 patients had a markedly positive test), equivocal in 11 patients (5.5%) and negative in 157 patients (78.5%). The patients were followed with serial pre- and postoperative electrocardiograms (ECGs) and determinations of serum creatine kinase (CK) and CK-MB. Six patients (3%) had primary endpoints: 3 (1.5%) died postoperatively and 3 (1.5%) had definite postoperative myocardial infarction. Secondary endpoints of suspected postoperative myocardial ischemia/injury diagnosed by ECG or elevation in CK-MB levels occurred in 27 patients (14%). Endpoint events were more common in patients aged 70 years or older. Endpoint events were also more common in patients with an abnormal (positive or equivocal) preoperative exercise test response than in those with a negative response (27% vs 14%); however, preoperative exercise results were not statistically significant independent predictors of cardiac risk. Using multivariate analysis, the only statistically significant independent predictor of risk was the preoperative ECG. Endpoint events were more common in patients with an abnormal than in those with a normal ECG (23% vs 7%, p less than 0.002). Because the results of exercise testing do not appear to add substantially to the risk separation provided by the ECG at rest, exercise testing is not recommended as a routine preoperative method for assessing perioperative risk in older patients who are being evaluated before major elective noncardiac surgery under general anesthesia.

Usefulness of self-efficacy in predicting overexertion during programmed exercise in coronary artery disease.

Overexertion during group jogging was evaluated in relation to self-perceived functional capacity and ability to self-monitor exertional heart rate in 40 men, mean age 55 +/- 9 years, with documented coronary artery disease. Patients' confidence in their ability to jog various distances was measured with a jog self-efficacy (SE) scale before a group exercise program was begun. Depression, type A personality, and performance of symptom-limited treadmill exercise were also assessed. Later, each patient was monitored with ambulatory (Holter) electrocardiography during programmed group jogging. Ambulatory monitoring disclosed significant noncompliance with exercise prescriptions: 33% of patients exceeded their prescribed range of 70% to 85% of maximal treadmill heart rate for at least 10 minutes of the 20-minute exercise bout. Another 25% spent 10 minutes or longer exercising below the prescribed range. Pretest jog SE predicted the number of minutes patients exercised above or below the prescribed intensity, but depression, type A and treadmill performance measures did not. Self-monitoring accuracy (the amount of agreement between exercise heart rate recorded by the electrocardiogram and by the patient) was also related to the number of minutes patients exercised outside the prescribed range. Comparison of SE and self-monitoring accuracy variables revealed that "overachievers" were patients who overestimated their ability to jog, while "underachievers" were those who overestimated their heart rate during exercise. Self-perceptions and self-monitoring skills appear to be important independent predictors of behavioral compliance to exercise guidelines.

Resistive training safety and assessment guidelines for cardiac and coronary prone patients.

The past few years have seen increased use of resistive training programs for cardiac and coronary prone individuals. There is growing evidence that using moderate resistance with frequent repetitions is safe and beneficial. This review provides guidelines for selection and assessment of patients for resistive training programs. For the most part, the criteria for participation in resistive training are the same as those used for the more traditional cardiac and high risk exercise programs.

Self-efficacy mediates strength gains during circuit weight training in men with coronary artery disease.

Motivation to engage in health-promoting exercise has been ascribed to global personality traits such as self-esteem or athletic self-confidence. Self-Efficacy Theory challenges this view by proposing that highly specific estimates of personal capabilities mediate adoption of new or difficult behavior patterns. We tested this assumption by measuring self-efficacy perceptions in 40 men with coronary artery disease who participated in an experiment evaluating effects of circuit weight training (CWT). Specific self-efficacy estimates were assessed during baseline strength/endurance testing and after 10 wk participation in CWT or volleyball. Correlational analyses of self-efficacy in relation to performance on strength/endurance tests strongly supported the contention that adoption of novel activities is governed by highly specific self-perceptions. Participation in CWT produced greater strength and endurance gains than did volleyball, and these changes were accompanied by increased self-efficacy in CWT subjects for activities resembling the training tasks. The assertion that self-efficacy perceptions directly mediate involvement in challenging physical activities was supported by multiple regression analyses. These revealed that pre-training self-efficacy judgments predicted post-test strength gains even after controlling for baseline strength, type of training and frequency of participation in exercise sessions.

Effects of diltiazem or propranolol during exercise training of hypertensive men.

This was a prospective, randomized, double-blind, placebo-controlled trial to establish whether beta blockers or calcium-channel blockers limit exercise capacity and training responses in men with mild hypertension. Circuit weight and aerobic training was used to assess the effects of drugs on cardiovascular fitness and muscle strength. Fifty-two sedentary men, ages 25-59 yr, with a diastolic blood pressure of 90-105 mm Hg off drugs, without significant ST depression during maximal stress testing, received diltiazem, propranolol, or placebo. Maximal oxygen uptake (VO2max) and exercise duration during treadmill testing, as well as one-repetition maximal strength, were assessed on eight weight machines after a single-blind placebo baseline, after 2 wk of drug run-in, and after 10 wk of exercise training. Total daily doses were 240 mg for propranolol and 360 mg for diltiazem. Propranolol decreased VO2max after drug run-in (P less than 0.05). Exercise training increased VO2max (P less than 0.05) in the diltiazem and placebo groups. After training VO2max in the propranolol group increased (P less than 0.05) from run-in but not beyond baseline levels. Thus, the reduction of VO2max consequent to propranolol therapy limited the overall benefits of training. Exercise duration did not change with run-in and increased (P less than 0.05) with training by 22%, 19%, and 10% for the diltiazem, placebo, and propranolol groups, respectively. Strength after run-in was unchanged, and exercise training increased strength (P less than 0.0001) on all weight machines in all groups. The results show an advantage of diltiazem to propranolol, particularly among physically active patients engaged in aerobic exercise who require antihypertensive therapy.

The preoperative electrocardiogram as an indicator of risk in major noncardiac surgery.

In this series of 198 patients studied prospectively before major noncardiac surgery, we previously reported that an abnormal preoperative electrocardiogram was a statistically significant independent predictor of an increased risk of postoperative complications, i.e., death, myocardial infarction, or myocardial ischemia. We therefore carried out a detailed analysis of the preoperative electrocardiographic (ECG) findings using Minnesota code criteria. Both ST-T abnormalities and intraventricular conduction delays showed a statistical trend toward a higher frequency in patients with a complicated vs. an uncomplicated postoperative course (82% vs. 59% and 24% vs. 7%, respectively). Although only a minority of patients with either ECG finding actually developed a complication (22% and 40% respectively), the preoperative ECG appears to be a useful screening method, with ST-T abnormalities and intraventricular conduction delays identifying patients at increased risk for postoperative complications.

Hypotension accompanying the onset of exertional angina. A sign of severe compromise of left ventricular blood supply.

Serious obstructive coronary artery disease was found in all patients who developed hypotension accompanying the onset of angina during multistage exercise testing. Seventeen exercising patients demonstrated a fall in systolic pressure to below resting levels as chest pain and ST-segment depression appeared. Two patients died suddenly six weeks after treadmill testing and prior to arteriography. The remaining fifteen were studied with coronary arteriography and all except one exhibited greater than or equal to 90% stenosis of the left anterior descending artery (LAD). The remaining patient demonstrated two 75% LAD stenoses in series. Five exhibited significant (greater than or equal 75%) narrowing of the main left coronary artery (MLCA) and thirteen of fifteen had significant stenosis of proximal LAD and circumflex arteries. The two patients without significant circumflex disease exhibited greater than or equal to 90% stenosis of the dominant right coronaryartery (RCA) circulation. Six of six patients had restoration of a normal blood pressure response following coronary bypass surgery, which also relieved angina and reversed ST-segment depression. Conditions essential for proper interpretation of this sign are discussed. If these conditions are met, then a fall in systolic pressure during treadmill-induced angina pectoris is a reliable sign of severe compromise of left ventricular blood supply.

Acute cardiogenic pulmonary edema in the elderly: factors predicting in-hospital and one-year mortality.

This prospective evaluation of 55 consecutive patients, aged 60 years or older, admitted in 1977-1978 to a community hospital coronary care unit for treatment of cardiogenic pulmonary edema, examines morality during hospitalization and during the subsequent one-year follow-up. Their treatment was based on clinical criteria, without the "advantage" of Swan-Ganz catheters and before widespread use of vasodilators for severe congestive heart failure. Multiple clinical and laboratory features were reviewed to determine possible prognostic clues. The nine patients who died during the initial hospitalization provided several clues to immediate mortality, including admission systolic blood pressure of less than 150 mm Hg, dyspnea for more than four hours, and peak creatine kinase values greater than 1,000 IU/L. The study identified high-risk patients who may benefit from more aggressive in-hospital therapy. The one-year mortality among the 46 patients discharged from the hospital was high (43%). Most noninvasive methods were not useful in attempting to predict one-year survival. The important question of whether newer therapeutic methods including vasodilators will favorably alter the relatively poor long-term prognosis in the elderly needs further study.

Exercise training combined with antihypertensive drug therapy. Effects on lipids, blood pressure, and left ventricular mass.

We studied exercise training combined with the use of antihypertensive drugs and examined the following questions. (1) Are there additive antihypertensive benefits with exercise and drug therapy combined? (2) Does drug therapy limit exercise-induced lipid improvements? (3) Does exercise that includes weight training and walking/jogging affect the left ventricle? Fifty-two hypertensive men were randomly assigned, double-blind, to diltiazem hydrochloride, sustained release (360 mg daily), propranolol hydrochloride (240 mg daily), or placebo and exercised three times per week for 10 weeks. Baseline blood pressure (145/97 mm Hg) fell after training (131/84 mm Hg) in all groups. Exercise decreased total and low-density lipoprotein cholesterol levels in all groups. Increases in the levels of high-density lipoprotein cholesterol were similar in placebo and diltiazem groups, whereas the propranolol group changed in an opposite direction. In all groups, left ventricular mass increased with training, while diastolic function was unchanged. We conclude that (1) drug therapy provided no additive benefit to the antihypertensive effects of exercise, (2) propranolol limited improvements in high-density lipoprotein cholesterol, and (3) exercise did not adversely affect the left ventricle.

Technetium-99m-pyrophosphate scintigraphy in patients with suspected acute myocardial infarction: impact of interobserver variability.

Technetium-99m-pyrophosphate (TcPYP) scintigraphy may have great value in patients with suspected acute myocardial infarction (AMI), but interobserver variability undoubtedly has adverse impact on predictive value. TcPYP scintigrams for 133 (80%) of 166 consecutive patients admitted for suspected AMI were interpreted independently by three experienced readers. Although there was complete agreement for 87 interpretations (65%), major discrepancies (i.e., at least one positive and one negative reading on the same scan) occurred for 28 scans (21%). To assess predictive accuracy, patients were categorized as follows: 36 had definite AMI manifest by new ECG Q waves and/or CK-MB evidence of AMI (group I), 56 were classified as possible AMI (group II), and 41 had AMI excluded (group III). Using only the definitive diagnostic categories (groups I and III), accuracy for each reader approximated 0.68, with no single reader being correct more often than any other.