Abnormal left ventricular ejection fraction response to mental stress and exercise in cardiomyopathy.

BACKGROUND: A decline in left ventricular (LV) ejection fraction in response to mental stress and exercise is regarded as an indicator of myocardial ischemia. In patients with LV dysfunction, the ejection fraction is sensitive to afterload, which increases during stress. Thus, the effects of mental stress and exercise on LV systolic function in patients with cardiomyopathy were examined. METHODS: The ambulatory nuclear VEST (Capintec, Inc., Ramsey, N.J.) was used to monitor LV ejection fraction in patients with cardiomyopathy (10 idiopathic and 9 ischemic). Patients underwent a series of mental stress tests (serial 7s, Stroop color, and Paced auditory addition) and treadmill exercise. Heart rate, systolic blood pressure, and LV ejection fraction were measured. RESULTS: Mental stress and exercise increased heart rate and systolic blood pressure. For idiopathic cardiomyopathy, LV ejection fraction decreased during serial 7s, Stroop color, Paced auditory addition and exercise by -8% +/- 6%, -7% +/- 5%, -7% +/- 3%, -9% +/- 10%, respectively. For ischemic cardiomyopathy, LV ejection fraction declined by -4% +/- 3%, -7% +/- 5%, -6% +/- 3%, -2% +/- 6% during the same stress tests. There was no difference between the idiopathic and ischemic groups. Each patient showed a 5% or greater decline in LV ejection fraction during one mental stress test. There was an inverse relation between changes in LV ejection fraction and systolic blood pressure during all mental stress tests and exercise (r = -0.47, p < 0.0001). CONCLUSIONS: In patients with depressed baseline systolic function, the decline in systolic function during mental stress and exercise could be related in part to increases in LV afterload.

Relationship between hemodynamics and right ventricular function in patients with cardiomyopathy. Important role of tricuspid regurgitation.

STUDY OBJECTIVE: Right ventricular (RV) ejection fraction is load sensitive, varying inversely with pulmonary artery pressure. We tested whether this relationship exists in dilated cardiomyopathy. DESIGN: Retrospective chart review. SETTING: Tertiary care referral medical center. PATIENTS: In 25 patients with cardiomyopathy referred for heart transplant evaluation (left ventricular ejection fraction 27 +/- 12%), hemodynamics, radionuclide angiograms, and Doppler echocardiograms were obtained initially (study A) and 8 +/- 8 months later (study B). RESULTS: Right ventricular ejection fraction was 40 +/- 17% on study A and 41 +/- 16% on study B, with a wide range of change between studies (+38 to -28%). Pulmonary artery systolic pressure (PASP) and right atrial pressure increased (52 +/- 9 to 61 +/- 10 mm Hg and 10 +/- 4 to 14 +/- 4 mm Hg, respectively, p < 0.05). There was no relation between PASP and RV ejection fraction (n = 50, r = -0.02, p = 0.87). Also, there was no relation between changes in PASP and RV ejection fraction (n = 25, r = 0.25, p = 0.15) between study A and B. However, there was a significant relation between interstudy changes in PASP and RV ejection fraction (n = 14, r = -0.71, p = 0.005) and end-systolic volume (n = 14, r = 0.53, p < 0.05) in patients in whom the degree of tricuspid regurgitation was either none or mild on both study A and B. CONCLUSIONS: In patients with cardiomyopathy, RV ejection fraction cannot be used as a noninvasive marker of pulmonary hypertension. Owing to variation in tricuspid regurgitation, alterations in pulmonary artery pressure over time may not lead to the expected change in RV ejection fraction or end-systolic volume.

Rest-redistribution thallium-201 scintigraphy to determine myocardial viability early after myocardial infarction.

OBJECTIVES: This study attempted to determine the utility of early rest-redistribution thallium-201 imaging in detecting residual myocardial viability after myocardial infarction. BACKGROUND: The early detection of myocardial viability after myocardial infarction would have clinical relevance. METHODS: Thirty-one patients with acute myocardial infarction had early (mean [+/- SD] 2 +/- 1 day) rest-redistribution thallium-201 imaging followed by radionuclide and coronary angiography. Late studies included stress-redistribution-reinjection thallium-201 imaging or radionuclide angiography, or both. Viability was defined by the rest thallium-201 scan as an initial mild rest defect or any defect that demonstrated redistribution. RESULTS: Group 1 (n = 15) was predicted to have viable and Group 2 (n = 16) nonviable myocardium in the infarct zone. Group 1 patients were more likely to have a patent infarct-related artery (15 of 15 vs. 10 of 16, p < 0.03), higher initial ejection fraction (61 +/- 12% vs. 53 +/- 9%, p < 0.05), higher infarct wall motion score (p < 0.0001) and fewer abnormal thallium-201 segments (p < 0.0001). On follow-up studies, ejection fraction improved in Group 1 (from 57 +/- 13% to 66 +/- 10%, p < 0.05, n = 9) and deteriorated in Group 2 (from 53 +/- 10% to 46 +/- 8%, p < 0.05, n = 13). On late stress testing with thallium-201 reinjection, Group 1 patients had fewer abnormal segments (p < 0.03) and higher infarct zone counts during exercise (p < 0.05) and after reinjection (p < 0.05) than Group 2 patients. CONCLUSIONS: If confirmed by larger studies, early rest-redistribution thallium-201 imaging may be a useful technique for identifying residual viability after myocardial infarction.

Effects of chronic right ventricular pressure overload on left ventricular diastolic function.

Right ventricular (RV) function influences left ventricular (LV) diastolic filling in various clinical and experimental models. The influence of RV systolic function on LV diastolic performance was examined in patients with severe RV pressure overload. Eighty-two patients with pulmonary vascular or parenchymal disease who were referred for heart-lung or lung transplant evaluation were studied. All patients had radionuclide angiography from which RV ejection fraction and LV peak filling rate were measured. Most patients (n = 51) had right-sided cardiac catheterization. In 24 patients (group 1), RV ejection fraction was < 30%, whereas in 58 (group 2), it was > 30%. Mean pulmonary artery pressure was greater in group 1 than in 2 (57 +/- 16 vs 34 +/- 20 mm Hg; p < 0.0001). Pulmonary artery wedge pressure was also greater in group 1 than in 2 (14 +/- 9 vs 7 +/- 2 mm Hg; p < 0.0001), whereas peak filling rate was decreased (2.16 +/- 0.88 vs 2.97 +/- 0.79 end-diastolic volumes/s; p < 0.0001). LV ejection fraction was normal in all patients. There was an inverse relation between RV ejection fraction and pulmonary artery wedge pressure (r = 0.45; p < 0.001; SEE 5.3). There was a direct relation between RV ejection fraction and LV peak filling rate (r = 0.49; p < 0.0001; SEE 1.34). In patients with RV pressure overload, RV systolic function is related to LV diastolic performance. This effect is most likely mediated by ventricular interdependence.

Right ventricular thallium-201 kinetics in pulmonary hypertension: relation to right ventricular size and function.

Right ventricular ischemia occurs in experimental models of pulmonary hypertension. We analyzed right ventricular size and function and 201Tl uptake to determine if there was a relationship between 201Tl uptake and systolic function in 19 patients with pulmonary artery hypertension who were being evaluated for heart-lung transplantation. All patients had dipyridamole stress 201Tl scintigraphy, radionuclide angiography and echocardiography. In nine patients (Group 1), right ventricular ejection fraction was < 30% (mean 22% +/- 8%). In 10 patients (Group 2) it was > 30% (mean 45% +/- 11%). In Group 1, right ventricular 201Tl uptake in the lateral wall after dipyridamole was increased compared to Group 2 (40% +/- 7% versus 28% +/- 15% counts/pixel, p < 0.05) while left ventricular free wall uptake was similar. The ratio of right to left ventricular 201Tl uptake was increased in Group 1 versus Group 2 (0.81% +/- 0.30% versus 0.49% +/- 0.18%, p < 0.05). At 4 hr, right ventricular free wall 201Tl clearance was comparable, 51% +/- 13% versus 51% +/- 18% in Groups 1 and 2, respectively. No patient had perfusion abnormalities. Right ventricular ejection fraction was inversely related to dipyridamole stress right ventricular 201Tl uptake, r = -0.49, p < 0.03, s.e.e. = 13.6. Right ventricular 201Tl uptake was directly related to right ventricular wall thickness (r = 0.56, p = 0.18, s.e.e. = 10.4). Therefore, patients with more severe right ventricular systolic dysfunction have greater 201Tl uptake after dipyridamole stress, suggesting increased myocardial mass and possibly blood flow in response to hypertrophy. Patients with the most marked hypertrophy have impairment of right ventricular systolic function, independent of ischemia.

Usefulness of thallium-201 for distinction of ischemic from idiopathic dilated cardiomyopathy.

Thallium-201 scintigraphic defects are observed in most patients with ischemic cardiomyopathy and also can be found in idiopathic dilated cardiomyopathy. To determine the ability of qualitative and quantitative perfusion parameters to differentiate these entities, thallium-201 exercise testing was performed in 51 patients with coronary arteriography referred for evaluation of severe congestive heart failure. All patients had a left ventricular ejection fraction < 35%. Thirty-one ischemic patients had coronary stenosis > 70% in > or = 1 artery, and 20 idiopathic patients had no coronary stenosis or identifiable cause of heart disease. Similar exercise capacity, ejection fraction and sex distribution were found in both groups. Ischemic patients more often had severe perfusion defects (97 vs 25%; p = 0.00001), large perfusion defects involving > or = 40% of the left ventricular contour (100 vs 80%; p = 0.01), and increased thallium-201 lung uptake (94 vs 65%, p = 0.01). Large severe defects were present in 90% of ischemic and only 5% of idiopathic patients. On quantitative analysis, the area of the thallium-201 curve less than normal was greater in ischemic than idiopathic patients (14.8 +/- 9.5% vs 3.3 +/- 2.8%; p = 0.001). The degree and severity of redistribution were similar in both groups. Multivariate analysis identified the qualitative parameters of increased thallium-201 lung uptake, severe defects and large severe defects as the only independent predictors of the presence of ischemic disease. The presence of large severe defects had a 97% predictive value for ischemic cardiomyopathy. The absence of severe defects had a 94% predictive value for idiopathic dilated cardiomyopathy.(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical cardiomyoplasty: preoperative factors associated with outcome.

Dynamic cardiomyoplasty has been used clinically to augment the ventricular function of a failing heart. Fifteen clinical dynamic cardiomyoplasties have been performed at Allegheny General Hospital since 1985. Left ventricular ejection fraction improved in long-term survivors from a preoperative value of 0.23 +/- 0.02 to 0.32 +/- 0.05 with postoperative cardiomyostimulation (p < 0.05). There was an average reduction of 2 +/- 0.3 New York Heart Association classes (3.6 +/- 0.2 before operation versus 1.6 +/- 0.4 after operation; p < 0.001). Postoperative mortality was 27% (4/15), and early mortality (within 6 months after operation) was 20% (3/15). Significant preoperative differences between survivors and nonsurvivors were found in right ventricular ejection fraction (0.53 +/- 0.03 versus 0.30 +/- 0.07; p < 0.05), pulmonary artery mean pressure (19 +/- 2 versus 34 +/- 6 mm Hg; p < 0.05), pulmonary artery diastolic pressure (12 +/- 1 versus 25 +/- 5 mm Hg; p < 0.05), and pulmonary vascular resistance (1.4 +/- 2 versus 2.5 +/- 0.7 Wood units; p < 0.05). Dynamic cardiomyoplasty can be done with low operative mortality in patients with isolated left ventricular failure, but mortality is high in those with biventricular failure or pulmonary hypertension. Improvement in functional class and ventricular function can be expected in long-term survivors. Application of these findings to patient selection will improve the risk/benefit ratio for dynamic cardiomyoplasty.

Surgical therapy for congestive heart failure: indications for transplantation versus cardiomyoplasty.

Heart transplantation is the procedure of choice for patients with severe congestive heart failure, but many patients are not candidates because of associated medical problems and the lack of donor hearts. Since 1988 we have performed 36 heart transplantations. One and 2-year actuarial survival rates have been 82% and 73%. Sixteen patients who were not candidates for heart transplantation have undergone cardiomyoplasty, a procedure in which the left latissimus dorsi is transposed to the myocardium and paced synchronously with the heart to augment cardiac function. The average age was 55 years (range, 39 to 65 years). Preoperative left and right ejection fractions were 24.9% +/- 2.1% and 43% +/- 4.5%. Eleven patients were in the New York Heart Association class IV, and five patients were in class III. Four operative deaths occurred, and three additional deaths occurred within 6 months of surgery. Nine patients became long-term survivors, and seven of nine patients are alive at a mean follow-up of 29 months. All patients are in New York Heart Association class I or II. In long-term survivors, mean left ventricular ejection fraction increased from 24.9% +/- 2.1% to 31.8% +/- 3.5% (p less than 0.01). All but one of the operative and early deaths occurred in patients with biventricular failure (n = 6). One operative death and no early deaths occurred in patients with normal right ventricular ejection fraction. This initial experience suggests that cardiomyoplasty may be helpful for heart failure patients with preserved right ventricular function, but heart transplantation should be the therapy of choice for biventricular failure.

A controlled clinicopathologic study of myocardial fibrosis in systemic sclerosis (scleroderma).

Clinicopathologic correlations of myocardial fibrosis were examined in 54 autopsied patients with scleroderma and 54 age and sex matched autopsy controls. Thirty eight (70%) of the patients with scleroderma had myocardial fibrosis compared to 20 (37%) of the controls (p less than 0.005). There was no significant difference in the prevalence of contraction band necrosis in the patients with scleroderma (22%) compared to controls (17%). Patients with scleroderma with left ventricular dysfunction in the absence of other causative factors clinically had a greater prevalence of both advanced myocardial fibrosis (60%) and contraction band necrosis (40%) than did the other patients with scleroderma or the controls. We conclude that patients with scleroderma with the greatest likelihood of advanced myocardial fibrosis can be identified clinically, and their findings are consistent with the presence of microvascular coronary vasospasm, a "myocardial Raynaud's phenomenon."

Cardiomyopathy. 2. Hypertrophic and restrictive/obliterative types.

The functional classification of the three types of cardiomyopathy has been helpful in organizing practitioners' thinking. The past three decades have witnessed tremendous advances in understanding of the pathophysiology, clinical and laboratory diagnosis, and treatment of these disorders. New doors of exploration are opening to answer such nagging questions as whether medical therapy alters long-term survival rates in dilated (congestive) cardiomyopathy, whether immunologic therapy will alter the course of dilated or restrictive/obliterative cardiomyopathy, and whether genetic manipulation or in utero therapy will prevent hypertrophic cardiomyopathy. The goals of effective treatment in all these disorders remain the same: amelioration of symptoms, prevention of sudden death, and constraint or resolution of the basic disease process. Achieving these goals requires a multidisciplinary approach, involving cardiologists, surgeons, immunologists, geneticists, cell biologists, virologists, and pathologists. Prospects are that one day treatment will no longer be an imprecise, palliative art but a definitive, curative science.