Prospective multicenter study of pregnancy outcomes in women with heart disease.

BACKGROUND: The maternal and neonatal risks associated with pregnancy in women with heart disease receiving comprehensive prenatal care have not been well defined. METHODS AND RESULTS: We prospectively enrolled 562 consecutive pregnant women with heart disease and determined the outcomes of 599 pregnancies not ending in miscarriage. Pulmonary edema, arrhythmia, stroke, or cardiac death complicated 13% of pregnancies. Prior cardiac events or arrhythmia, poor functional class or cyanosis, left heart obstruction, and left ventricular systolic dysfunction independently predicted maternal cardiac complications; the cardiac event rate can be predicted using a risk index incorporating these predictors. Neonatal complications (20% of pregnancies) were associated with poor functional class or cyanosis, left heart obstruction, anticoagulation, smoking, and multiple gestations. CONCLUSIONS: Pregnancy in women with heart disease is associated with significant cardiac and neonatal complications, despite state-of-the-art obstetric and cardiac care. Maternal cardiac risk can be predicted with the use of a risk index.

Comparison of ejection fraction and pulmonary blood volume ratio as markers of left ventricular function change after coronary angioplasty.

Exercise-induced increases in pulmonary blood volume ratio have been shown to be a sensitive marker of coronary artery disease, and correlate well with exercise-induced increases in left ventricular filling pressure. To compare the impact of single vessel coronary disease on left ventricular systolic function (ejection fraction) versus diastolic filling pressure (pulmonary blood volume) before and after intervention, serial supine exercise gated blood pool scans were performed before and after coronary angioplasty in 32 patients with isolated left anterior descending coronary artery disease. By applying previously established criteria of abnormal ejection fraction (rest less than 50% or failure to rise by 5% with exercise) and pulmonary blood volume ratio (greater than 1.06), 66% of the patients were found to have abnormal responses before angioplasty by ejection fraction compared with 81% abnormal responses by pulmonary blood volume ratio (p = 0.15). After angioplasty, the proportion of patients with abnormal ejection fraction (59%) was essentially unchanged, whereas only 38% continued to have an abnormal pulmonary blood volume ratio (p less than 0.01 compared with before angioplasty). The mean pulmonary blood volume ratio also decreased significantly from 1.15 +/- 0.10 before angioplasty to 1.02 +/- 0.15 after angioplasty (p less than 0.001). It is concluded that in single vessel coronary artery disease: 1) pulmonary blood volume ratio is abnormal at least as frequently as is ejection fraction; 2) in contrast to ejection fraction, pulmonary blood volume ratio improves significantly after successful angioplasty; and 3) pulmonary blood volume ratio may be a more sensitive indicator of changes in ventricular function after an intervention in single vessel coronary disease.

Evaluation of bepridil for the treatment of angina pectoris: evidence for preservation of left ventricular function.

The efficacy of bepridil (400 mg once a day) was assessed in 15 patients with exertional angina pectoris. All 15 patients reported substantial clinical improvement during bepridil treatment compared with placebo treatment. Episodes of angina were 11.8 +/- 4.1 (mean +/- standard error of the mean)/week with placebo and 3.8 +/- 1.6 with bepridil (p less than 0.05); nitroglycerin use was 9.1 +/- 3.3 tablets/week with placebo and 3.5 +/- 1.7 with bepridil (p less than 0.05). Five of 15 patients receiving bepridil did not experience angina during treadmill exercise; in the remaining 10 patients, time to onset of angina during exercise was 5.7 +/- 0.9 minutes with bepridil as opposed to 4.5 +/- 0.8 minutes with placebo (p less than 0.05). Left ventricular (LV) performance at peak exercise as measured by first-pass radionuclide angiography revealed the ejection fraction to be 38 +/- 3% during placebo therapy and 47 +/- 4% during bepridil therapy (p less than 0.0025). End-diastolic LV volume was unchanged, but end-systolic volume was 136 +/- 11 and 117 +/- 13 ml (p less than 0.05) and stroke volume was 82 +/- 6 and 97 +/- 9 ml (p less than 0.05) during placebo and bepridil therapy, respectively. Heart rate at peak exercise was 136 +/- 3 beats/min with placebo and 128 +/- 3 beats/min with bepridil; however, blood pressure was unchanged. These studies demonstrate that bepridil results in significant clinical improvement and enhanced LV performance in patients with angina pectoris.

Cardiac dysfunction associated with the acquired immunodeficiency syndrome (AIDS).

Five patients with acquired immune deficiency syndrome (AIDS) developed clinical evidence of mild to severe cardiac dysfunction confirmed by nuclear angiography and echocardiography. In 4 patients who were studied postmortem there was no evidence of myocarditis, valvular, or ischemic heart disease. Cardiac involvement in patients with AIDS may include pericardial and myocardial involvement by opportunistic pathogens or Kaposi's sarcoma, subclinical myocardial dysfunction, or an as-yet unexplained cardiomyopathy.

Malnutrition and the heart.

Earlier concepts that the heart is spared in malnutrition have been shown to be incorrect. Inadequate intake of protein and energy results in proportional loss of skeletal and myocardial muscle. As myocardial mass decreases, so does the ability to generate cardiac output; however, various compensatory factors come into play. Nutritional supplementation for malnourished patients reverses the compensatory factors and may increase the short-term potential for heart failure. Severe cardiac debility results in poor nutrition, which may in turn produce unsuspected but clinically significant myocardial atrophy. Nutritional support may play a role in improving cardiac function in selected patients with cardiac cachexia who are being prepared for cardiac surgery and in patients with rapid weight loss who are at risk for sudden death due to arrhythmias. Malnutrition is common in hospitalized patients, and many patients in hospital now receive nutritional supplementation; both facts have important cardiac implications.

Northern exposure: nuclear cardiology in the Canadian health care system.

The Canadian health care system may provide valuable insights into the future practice of nuclear cardiology in the United States. Rationing of medical care is not legislated by the Canadian health care system, although resource allocation is required of Canadian physicians and hospital administrators. Canadian nuclear cardiologists and physicians are not restricted in the ordering of diagnostic studies, despite the decreased availability in imaging systems and the centralization of equipment and personnel in Canada. Canadian imaging equipment is, in general, used more with less average idle time per unit. Delays in the performance of nonemergent imaging studies are more common in Canadian imaging laboratories. The number of out-of-hospital nuclear medicine laboratories is not increasing, because of government constraints on licensing and the general requirement that only radiologists or certified nuclear medicine physicians can operate these laboratories. A survey of 71 nuclear cardiology laboratories in the United States and Canada reveal that 21% of all cardiac imaging studies are performed for post-myocardial infarction risk stratification in Canada, compared with only 11% in United States laboratories. Rest and reinjection thallium imaging studies are performed more than twice as often in the United States laboratories. Canadian laboratories perform a higher average number of myocardial perfusion (2123 vs 1789) and ventricular function (773 vs 554) studies as compared with their United States counterparts. No other significant differences in clinical usage patterns were identified. A total of 130,000 nuclear cardiologies were performed in Canada in 1993, with less than 5% growth in the number of Canadian studies projected for 1994. Forty-five percent of Canadian perfusion studies are performed with 99mTc-labeled sestamibi frequently using a 2-day protocol (60%) with electrocardiogram gating (30%). Positron emission tomography (PET) can be performed in only six Canadian cities. Canadian PET centers are government funded, located in university teaching hospitals, and principally used for the purpose of research. Stress echocardiography is not widely performed in Canada because of the heavy clinical volume of standard echocardiographic studies at most hospitals, which reduces the time available for stress echocardiography. No separate billing code is available for stress echocardiography studies in Canada. Canadian cardiologists have accepted the value of rest and stress nuclear studies for the management of their patients and have concluded that it is more time efficient to perform clinical duties in lieu of stress echocardiographic studies. In conclusion, the realities of the Canadian health care system are that universal health care is valuable as long as it is consistent high quality medical care, and that the cost of universal coverage must be borne by the taxpayer using the system. The fact that nuclear cardiology has continued to thrive in the Canadian health care system suggests that future health care modifications in the United States will not exert a significant impact on the practice of nuclear cardiology.

The effects of stress on left ventricular ejection fraction.

The left ventricular ejection fraction (EF) was studied in 17 healthy volunteers with a new ambulatory left ventricular function monitor. Heart rate, EF, and blood pressure measurements were made during rest, a psychiatric stress interview, cold exposure, exercise, and eating. An increase in EF was seen during emotional stress (from 0.45 +/- 0.09 to 0.51 +/- 0.13, P less than 0.001). This increase was comparable to that observed during exercise (0.52 +/- 0.14) and eating (0.52 +/- 0.10, P less than 0.001). In contrast, cold exposure caused a decrease in EF (0.43 +/- 0.13, P less than 0.05). These observations demonstrate the powerful hemodynamic consequences of common behaviors as well as the utility and feasibility of studying such behavioral factors in ambulatory subjects.

The persistent defect on exercise thallium imaging and its fate after myocardial revascularization: does it represent scar or ischemia?

Persistent defects on serial thallium scans are commonly thought to represent fibrosis or scar. However, such a pattern may also represent severe ischemia. To better understand persistent defects, exercise thallium and resting gated blood pool scans were reviewed in 52 patients pre and post coronary angioplasty for single-vessel left anterior descending (LAD) coronary artery disease, and the fate of persistent defects after successful revascularization was determined. Persistent and transient defects were defined from the average scores of three observers. Ten patients with 16 myocardial segments with persistent defects were compared to another 11 patients with 20 myocardial segments with transient defects. After angioplasty (PTCA), 75% of the regions that had persistent defects and 85% of the regions that had transient defects were normal by visual assessment. In the persistent defect group, only regional wall motion on the resting gated blood pool scan pre PTCA helped to distinguish those segments that would or would not revert to normal. We conclude that regions of persistent defect on thallium scan often revert to normal after PTCA (75%), suggesting that persistent defects may represent hypoperfusion of viable myocardium, and should not preclude consideration of an intervention.

Efficacy of 15-(123I)-p-iodophenyl pentadecanoic acid (IPPA) in assessing myocardial metabolism in a model of reversible global ischemia.

In a canine model of reversible global ischemia, the residual quantity of 123I was assessed following a bolus injection of 15-p-(123I)-iodophenyl pentadecanoic acid (123I-IPPA). This technique was used to assess changes in free fatty acid metabolism following the utilization of three cardioplegic formulations. Cardioplegic arrest was initiated with Tyers' iso-osmolar (IO) solution (Group A); IO + superoxide dismutase (SOD) (Group B) and IO + allopurinol (Group C). Pre and post operative scanning were completed with 2-5 mCi 123I-IPPA. Clearance was assessed by IPPA time activity curve analysis generating t1/2 (half lives in min) for the early and late phases of the curve. The assessment between groups demonstrated that the elimination of 123I-IPPA products (early phase) was faster from the lateral wall in groups B and C versus group A (14 +/- 12 min, 13 +/- 9 min and 24 +/- 10 min, respectively). The elimination of IPPA (late phase) was also faster from the lateral wall in groups B and C when compared to group A (240 +/- 270 min, 132 +/- 85 min and 416 +/- 238 min). Examining the changes between control and postoperative values for each area of the left ventricle within each group demonstrated no significant changes for groups B and C. Group A, however, demonstrated significantly increased t1/2 values for the lateral wall (early and late phases) and the apical wall (late phase).(ABSTRACT TRUNCATED AT 250 WORDS)