Leonard E. Ginzton

Exercise Training Improves Left Ventricular Diastolic Filling in Patients With Dilated Cardiomyopathy Clinical and Prognostic Implications

BACKGROUNDnPatients with dilated cardiomyopathy (DCM) often have left ventricular (LV) diastolic dysfunction that can precede the development of systolic dysfunction. Recent reports showed that exercise training (ET) improves the exercise capacity of these patients. Although this improvement is primarily due to peripheral adaptations, the contribution of LV diastolic filling has not been well defined. The purpose of this study was to determine whether ET can induce changes in LV diastolic filling that can account for an increase in exercise capacity and whether these changes can influence prognosis.nnnMETHODS AND RESULTSnWe prospectively studied 55 consecutive patients (mean age, 55 +/- 7 years) with DCM. Patients were randomized into a training group (36 patients) or a control untrained group (19 patients) and matched for clinical and functional characteristics. All patients underwent a pulsed Doppler echocardiographic study, a radionuclide angiographic study, and a cardiopulmonary exercise test before and after a 2-month ET program. On the basis of the Doppler LV diastolic filling pattern at the beginning of the study, patients were prospectively divided into three subgroups: A (restrictive pattern), B (normal pattern), and C (abnormal relaxation pattern). In the trained group, peak VO2 (+12%; P < .0001), peak workload (+8.5%; P < .005), and lactic acidosis threshold (+12%; P < .0001) were significantly increased after training without changes in LV ejection fraction. However, only subgroup C demonstrated significant improvement in peak VO2 (+15%; P < .005). No changes were observed in the untrained group. In the trained subgroups a significant increase in rapid filling fraction (RFF), peak filling rate (PFR), peak early filling velocity (E), and E/A ratio was noted. A significant decrease in atrial filling fraction (AFF), peak atrial filling velocity (A), deceleration time of early filling velocity (EDT), and isovolumic relaxation time (IVRT) was observed only in subgroup C. No changes were found in untrained subgroups. A good correlation was found between Doppler and radionuclide LV diastolic filling parameters before and after training (P < .0001). Multiple stepwise regression analysis demonstrated that pretraining E/A ratio (P < .0001) and peak heart rate (P < .0002) were positive predictors of pretraining peak VO2. Posttraining increase in exercise tolerance (P < .0001) and increase in E/A ratio (P < .0001) were the strongest predictors of an increase in peak VO2. The independent predictors of cardiac events were a greater RFF and a shorter IVRT and EDT. Stepwise logistic regression showed that Doppler LV diastolic filling patterns are independent predictors of overall cardiac events (P = .02), and restrictive pattern has a worse prognosis compared with B (P = .04) and C (P = .007). However, ET did not reach statistical significance (P = .54) as a predictor of cardiac events.nnnCONCLUSIONSnThese data demonstrate that ET induces significant improvement in exercise capacity only in patients with DCM and a pattern of abnormal LV relaxation. The improvement in peak VO2 is significantly correlated with an increase in peak early filling rate and peak filling rate as well as a decrease in atrial filling rate. Doppler echocardiography may be a valuable tool in the prognostic assessment of patients with DCM who will benefit from exercise training.

Effects of Moderate Exercise Training on Thallium Uptake and Contractile Response to Low-Dose Dobutamine of Dysfunctional Myocardium in Patients With Ischemic Cardiomyopathy

BACKGROUNDnThere is evidence that exercise training can induce myocardial and coronary adaptations in both animals and humans. However, the significance of these potentially important changes remains to be determined in patients with ischemic heart disease and left ventricular (LV) systolic dysfunction.nnnMETHODS AND RESULTSnTo investigate whether exercise training can improve thallium uptake and the contractile response to low-dose dobutamine of dysfunctional myocardium, 46 patients (42 men, 4 women; mean age, 57+/-9 years) with chronic coronary artery disease and impaired LV systolic function (ejection fraction < 40%) were randomly assigned to two groups. The exercise group (n = 26) underwent exercise training at 60% of peak oxygen uptake for 8 weeks. The control group (n = 20) was not exercised. At baseline and after 8 weeks all patients underwent an exercise test with gas exchange analysis and stress echocardiography using low-dose dobutamine (5 to 10 microg/kg per minute) followed by thallium myocardial scintigraphy. Coronary angiography was performed in 23 patients at baseline and after 8 weeks. After 8 weeks, peak oxygen uptake increased significantly only in trained patients (24%). Significant improvements in the contractile response to dobutamine and thallium activity were observed in trained patients (28% and 31%, respectively; trained versus control: P<.001 for both). In a subgroup of trained patients, both improvements were correlated with an increase in the coronary collateral score (P<.005 and P<.001, respectively).nnnCONCLUSIONSnModerate exercise training improves both thallium activity and the contractile response of dysfunctional myocardium to low doses of dobutamine in patients with ischemic cardiomyopathy. The implication of this study is that even a short-term exercise training may improve quality of life by improvement of LV systolic function during mild-to-moderate physical activity in patients with ischemic cardiomyopathy.

The differential diagnosis of acute pericarditis from the normal variant: new electrocardiographic criteria.

We examined the quantitative electrocardiographic differentiation of acute pericarditis from normal variant ST/T changes. The ECGs of 19 patients with acute pericarditis were compared with those of 20 subjects with typical normal variant changes. Patients were excluded if their ECGs demonstrated conditions that markedly altered repolarization. The positive predictive values (PPV) and negative predictive values (NPV) of previously reported criteria were not high (PPV = 0.54-0.83, NPV = 0.56-0.58). In contrast, in the present study, a T-wave amplitude in lead VB of < 0.3 mV diagnosed acute pericarditis (p < 0.005, PPV = 0.85, NPV = 0.85), but there was overlap of patients between the groups. The ratio of the amplitude of the onset of the ST segment to the amplitude of the T wave in that lead (ST/T ratio in V.) proved to be the most reliable discriminator. An ST/T ratio 0.25 diagnosed all patients with acute pericarditis (p < 0.005, PPV = 1.0, NPV = 1.0). The ST/T ratio 0.25 in V,, V5 (both p < 0.005, PPV = 0.87, NPV = 1.0) and I (p < 0.005, PPV = 0.80, NPV = 0.81) were also significant discriminators. Thus, if V, is unavailable, an ST/T ratio 0.25 in V,, V, or I is highly suggestive of acute pericarditis. An ST/T ratio > 0.25 in V. discriminated the ECGs of all patients with acute pericarditis from normal variants in this study.

Noninvasive measurement of the rest and exercise peak systolic pressure/end-systolic volume ratio: A sensitive two-dimensional echocardiographic indicator of left ventricular function

Thirty-five patients with previous myocardial infarction and 25 normal subjects underwent subcostal view two-dimensional echocardiography at rest and at peak up-right bicycle exercise. The purpose was to assess changes in left ventricular volume with maximal upright bicycle exercise and to compare the utility of the peak systolic pressure/end-systolic volume index ratio and ejection fraction as indicators of left ventricular function. With exercise, normal subjects had a decrease in end-systolic volume index (22 +/- 8 to 11 +/- 3 ml/m2) (p less than 0.001); the normal ejection fraction (59 +/- 9 to 72 +/- 8%, p less than 0.001) and the pressure/volume ratio (6 +/- 3 to 18 +/- 6, p less than 0.001) increased. In patients with prior myocardial infarction there was no change in end-systolic volume index, ejection fraction or pressure/volume ratio with exercise. Although at peak exercise significant differences between normal subjects and patients with prior infarction were demonstrated in end-systolic volume index (p less than 0.001), ejection fraction (p less than 0.001) and pressure/volume ratio (p less than 0.001), the pressure/volume ratio provided sharper delineation between the two groups than did ejection fraction. The exponential relation of the pressure/volume ratio and ejection fraction at peak exercise demonstrates that the pressure/volume ratio is more sensitive as an indicator of normal or borderline left ventricular function and that ejection fraction is more sensitive in quantifying the degree of left ventricular dysfunction.(ABSTRACT TRUNCATED AT 250 WORDS)

Quantitative analysis of segmental wall motion during maximal upright dynamic exercise: variability in normal adults.

Twenty-five healthy adults underwent subcostal-view, four-chamber two-dimensional echocardiographic examination while upright at rest and at the peak of maximal bicycle exercise. The purpose of the study was to determine whether the variability in regional left ventricular endocardial motion, previously demonstrated to be present at rest, persisted at peak exercise. The rest and exercise end-diastolic and end-systolic endocardial contours were visually identified, digitized, and divided into 32 radial segments after realignment by the computer. At rest there was similar percent segmental area reduction for the septum (segments 1 to 12) (54 +/- 4%, mean +/- 1 SD), apex (segments 13 to 20) (67 +/- 3%), and lateral wall (segments 21 to 32) (67 +/- 8%). At peak exercise the percent area reduction increased significantly: septum 84 +/- 5%, apex 88 +/- 2%, lateral wall 83 +/- 6% (p less than .001 compared with rest for all areas). However, there was considerable variability in percent area reduction between different radial segments in the same individual. At rest the difference between minimal and maximal percent area reduction within the same individual was 49 +/- 17 percentage units (range 21 to 83) and that at peak exercise was 32 +/- 17 percentage units (range 0 to 66). It is concluded that, because the range of standard deviation of normal endocardial motion and the degree of variability between radial segments in the same healthy individual are significant, qualitatively determined hypokinesis, as commonly assessed clinically, may be a normal event. However, segmental akinesis or dyskinesis, which occurred rarely at rest and never at peak exercise, must be considered abnormal events.

Functional significance of hypertrophy of the noninfarcted myocardium after myocardial infarction in humans.

Hypertrophy of the noninfarcted left ventricle as a chronic response to myocardial infarction has been demonstrated in animals and at autopsy in humans. However, the functional significance of postmyocardial infarction hypertrophy is a subject of dispute. The purpose of this study was to determine the time course of development of postmyocardial infarction hypertrophy of the noninfarcted myocardium in humans and to assess its functional significance. Subcostal view, two-dimensional echocardiograms were recorded at rest and during peak exercise, 6 and 40 weeks postmyocardial infarction in 45 patients (16 anterior, 20 inferior, nine non-Q wave infarcts), for measurement of left ventricular mass and ejection fraction. The left ventricular mass index increased from 94 +/- 30 to 118 +/- 27 g/m2 (p less than 0.01) during the time of the two studies. There was a significant correlation between the change in left ventricular mass index and improved resting ejection fraction (r = 0.48, p less than 0.001) and exercise ejection fraction (r = 0.48, p less than 0.001) at the follow-up study. Of the 32 patients who increased their left ventricular mass index greater than 7%, 18 improved their rest ejection fraction greater than 0.05 units and 17 improved their exercise ejection fraction greater than 0.05 units. Conversely, of the 13 patients who failed to increase their left ventricular mass index, only three improved their rest ejection fraction and one improved the exercise ejection fraction (Fishers exact test, p less than 0.05). We reached three conclusions. First, in humans, significant hypertrophy of the noninfarcted myocardium can be detected by two-dimensional echocardiography, 9 months postmyocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)

Detection of multiple cardiac papillary fibroelastomas using transtsesophageal echocardiography

Papillary fibroelastomas are rare, benign cardiac tumors that may be associated with embolization, angina, and sudden death. We report a case of multiple papillary fibroelastomas diagnosed during life by transesophageal echocardiography. Surgical resection during mitral valve replacement for rheumatic mitral stenosis prevented the development of any of the life-threatening complications sometimes associated with this tumor.

Reduction aortoplasty for moderately sized ascending aortic aneurysms.

Abstractu2002 Enlargement of the ascending aorta may coexist with concomitant valvular, coronary, or other cardiac diseases. If dilation is moderate (i.e., < 6 cm diameter) and another cardiac procedure is being performed, we have reduced the diameter of the ascending aorta with an S‐shaped incision and excision of the curves of the “S” as a modified Z‐plasty. We have performed the procedure in 23 patients with concomitant procedures including aortic valve replacement in 21 (1 as a pulmonary autograft), coronary bypass in 1, and resection of subaortic stenosis in 1. There were 15 males and 8 females with a mean age of 53 years (range 8–67 years). The mean maximal pre‐operative diameter on transesophageal echocardiography was 5.0 ± 0.7 cm (range 3.2–6.6 cm). The mean intraoperative postreduction diameter was 3.1 ± 0.6 cm (range 2.1–4.1) (p < 0.01). All patients tolerated their procedures well. Sixteen patients were studied by transthoracic echocardiography postoperatively. These patients had a mean intraoperative postreduction diameter of 2.9 ± 0.65 cm that increased to 3.1 ± 0.45 cm (p = NS) after a mean follow‐up of 9.9 ± 12.6 months. Of these, seven patients were studied > 1 year postoperatively. Their mean intraoperative postreduction diameter of 2.9 ± 0.5 cm increased to 3.1 ± 0.35 cm (p = NS) after a mean follow‐up of 22.1 ± 9.2 months. No known recurrences of the aneurysms have occurred. We feel this technique is valid in patients with moderate aortic dilation undergoing concomitant cardiac procedures and in whom more aggressive aortic interventions are not warranted.

Electrocardiographic diagnosis of left ventricular hypertrophy in the presence of left bundle branch block

The electrocardiographic diagnosis of LVH in the presence of LBBB has previously been difficult. Thirty-seven patients with complete LBBB were identified and had echocardiography performed. Using an accepted echocardiographic formula, left ventricular mass was calculated. Twenty of the 37 patients (54%) were classified as having severe LVH. Multiple conventional ECG criteria for LVH were then evaluated. No QRS voltage criteria showed any difference between patients with and without LVH (P = NS). There was also no correlation between either QRS axis or left atrial enlargement and left ventricular mass (P = NS). However, the QRS duration was significantly longer in the patients with LVH (160 +/- 12 msec) than in the normal patients (148 +/- 11 msec) (P less than 0.001). The sensitivity, specificity, positive predictive value, and accuracy of several voltage criteria and QRS duration were examined. The best voltage criteria had a sensitivity of only 50% and a predictive value of 63%. However, a QRS duration greater than 155 msec had a sensitivity of 60% and a predictive value of 82%. This study demonstrates that the conventional QRS voltage criteria for LVH are not accurate in LBBB. A relationship exists between increasing QRS duration in LBBB and LVH; therefore, the relative probability adjectives: consider, possible, and probable should be used. QRS duration greater than 155 msec is predictive of LVH despite the presence of LBBB.

Closure of short, wide patent ductus arteriosus with cardiopulmonary bypass and balloon occlusion

The wide, short patent ductus arteriosus in adults and older adolescents poses an extreme hazard with standard closed ligation techniques. The method of transpulmonary balloon catheter occlusion and repair of pediatric ductus arteriosus is herein reported in older patients using a Foley catheter and normothermic bypass. Transesophageal echocardiography is crucial in assessing the size of the ductus and confirming adequacy of repair. The technique is simple and safe even in the presence of a wide, short ductus.