Echocardiography in congestive or dilated cardiomyopathy

Clozapine re-exposure after dilated cardiomyopathy

A 63-year-old woman with diabetes type II and a history of breast cancer was treated with clozapine for her refractory schizophrenia. She developed a dilated cardiomyopathy with an ejection fraction of 25%, a life-threatening event. The cause of heart failure could be multifactorial, with clozapine, family history, chemotherapy, diabetes type II and/or lithium as possible contributing risk factors. Clozapine was discontinued and the patient was referred to a hospice. Two weeks later, her heart failure slowly improved. Subsequently, she became extremely psychotic with a severe decline in quality of life. Therefore, it was decided to restart clozapine under cardiac monitoring. The patient's psychotic symptoms improved and her heart failure status remained stable for more than a year. Thereafter, a small deterioration was seen in cardiac function. In this case, re-exposure to clozapine was successful for at least 2 years.

Goldberger's electrocardiographic triad in patients with echocardiographic severe left ventricular dysfunction

In 1982, Goldberger described an electrocardiographic triad (SV1 or SV2 + RV5 or RV6 ≥ 3.5 mV, total QRS amplitude in each of the limb leads ≤ 0.8 mV, and R/S ratio < 1 in lead V4) that was 70% sensitive and > 90% specific for detecting severe left ventricular (LV) dysfunction. To confirm his sensitivity results, in 51 consecutive patients (36 men) aged 28 to 84 years (mean 56) with LV ejection fractions ≤ 20%, the electrocardiographic triad was sought in the electrocardiogram (ECG) recorded closest in time to the echocardiographic study. All 51 patients had systemic arterial hypertension. Evidence of ischemia was present in 7 and absent in 38, and in 6 patients, ischemic status was unknown. In 49 patients, New York Heart Association functional class was available: class II in 8, class III in 32, and class IV in 9. LV ejection fractions ranged from 4% to 20% (mean 14%), and LV internal end-diastolic diameters ranged from 5.7 to 8.6 cm (mean 6.6). Left atrial anteroposterior diameters ranged from 2.9 to 6.1 cm (mean 4.7) and were ≥ 4.0 cm in 47 of the 51 patients. The right ventricular cavity was enlarged in 22 patients. SV1 or SV2 + RV5 or RV6 was ≥ 3.5 mV in 29 of the 51 ECGs; total QRS amplitude was ≤ 0.8 mV in each of leads I, II, and III in 10; and the R/S ratio was < 1 in lead V4 in 37. Only 1 of the 51 ECGs met all 3 criteria. In contrast to Goldberger's finding of the triad to be 70% sensitive for severe LV dysfunction, in this study, the triad was found to be only 2% sensitive. The difference is likely due to his patients' having idiopathic dilated cardiomyopathy, whereas those in this study had hypertensive cardiomyopathy with or without ischemia. Also, in this study, 1 specific ECG was used for each patient, whereas Goldberger reviewed all of the patients' ECGs looking for the triad. In conclusion, Goldberger's triad is a sensitive or insensitive marker for severe LV dysfunction depending on the patient population and the number of ECGs reviewed.

Effects of dobutamine on left ventricular shape and geometry: an easy way to detect the functional status of chronic heart failure in patients with dilated cardiomyopathy

OBJECTIVE

Changes in left ventricular geometry and shape are prominent characteristics of cardiomyopathy. The aim of this study was to investigate left ventricular geometry and shape changes after inotropic stimulation in patients with chronic nonischemic dilated cardiomyopathy.

METHODS

A low infusion rate echocardiography-dobutamine study was performed in 35 consecutive patients (age: 50 +/- 8 years) with known dilated cardiomyopathy. Peak exercise oxygen consumption was measured the day before. Overall left ventricular chamber shape was assessed by using the long-/minor-axis dimension ratio obtained at end-diastole and end-systole.

RESULTS

After dobutamine infusion, in the entire study group an increase in systolic long-/minor-axis dimension ratio (0.11 +/- 0.13 mm, P <.001) was observed. The study population was further divided according to whether peak exercise oxygen consumption was less (group I) or more (group II) than 14 mL/kg/min. Although at baseline systolic long-/minor-axis dimension ratio was similar between groups, after dobutamine infusion it was higher in group II (1.51 +/- 0.19) than in group I (1.31 +/- 0.2, P <.01) indicating the abnormal response of systolic sphericity index to inotropic stimulation in patients with advanced functional class heart failure.

CONCLUSION

The response of systolic sphericity index to dobutamine infusion might be an alternative index of the functional status of the failing heart in patients with nonischemic dilated cardiomyopathy.

Usefulness of dobutamine stress tests for detection of cardiac abnormalities in dogs with experimentally induced early left ventricular dysfunction

OBJECTIVE

To determine whether dobutamine stress tests (DST) can be used to detect cardiac dysfunction in dogs with early left ventricular dysfunction (ELVD) induced by rapid right ventricular pacing (RRVP).

ANIMALS

7 adult male Beagles.

PROCEDURE

A pacemaker was surgically implanted in each dog at the level of the right ventricular apex. Electrocardiography, Doppler sphygmomanometry, and Doppler echocardiography were performed before and during a DST prior to activation of the pacemaker and every 3 to 4 days during the period of RRVP. Dobutamine stress tests were performed by infusing dobutamine at incremental dosages ranging from 12.5 to 42.5 microg/kg of body weight/min.

RESULTS

Clinical signs of congestive heart failure were not observed during the pacing period. However, all dogs developed ELVD associated with significant changes in values for most Doppler echocardiographic variables obtained prior to DST Adverse cardiac effects were not detected during DST. Most Doppler echocardiographic indices of cardiac function were significantly altered in response to dobutamine infusion during the pacing period, compared with prepacing values. However, a dobutamine-induced 2-fold increase in cardiac output was maintained.

CONCLUSIONS AND CLINICAL RELEVANCE

Dobutamine stress tests can be safely performed in dogs with experimentally induced ELVD. Dobutamine stress tests may be a sensitive, noninvasive diagnostic method, complementary to standard clinical examinations, for detection of early cardiac dysfunction in dogs asymptomatic for dilated cardiomyopathy.

Echocardiographic and Clinical Predictors of Mortality in Chronic Chagas' Disease

BACKGROUND: In a prospective epidemiological study of chronic Chagas' disease, several clinical and echocardiographic variables were analyzed as predictors of mortality. METHODS: Among 960 subjects seropositive for Chagas' disease who were examined between June 1981 and June 1992, 283 had echocardiograms. RESULTS: During a mean follow-up period of 48.3 +/- 36.4 months (range, 1-156 months), 108 subjects died. Echocardiographic end-diastolic and -systolic left ventricular internal dimensions, fractional shortening, radius-to-thickness ratio, left ventricular mass, mitral E-point septal separation, and 17 other nonechocardiographic variables were predictors of death on univariate analysis (P < 0.001 for each). On stepwise multiple regression analysis of 215 subjects, significant risk covariates in a Cox model analysis were clinical group (P < 0.0001), M-mode echocardiographic E-point septal separation of 22 mm (P = 0.003), presence of first- or second-degree heart block (P = 0.003), chest radiologic cardiothoracic ratio >/= 0.55 (P = 0.012), presence of electrocardiographic ST segment elevation on precordial leads (P = 0.014), age >/= 56 years (P = 0.028), and presence of right bundle-branch block (P = 0.045). Patients with an apical aneurysm on two-dimensional echocardiography had an increased mortality (Chi-square = 11.5, P < 0.001). CONCLUSIONS: Echocardiography is a valuable tool to assess the risk of death in prospective studies on chronic Chagas' heart disease.

Left ventricular remodeling with carvedilol in patients with congestive heart failure due to ischemic heart disease. Australia-New Zealand Heart Failure Research Collaborative Group

OBJECTIVES

The aim of this study, a substudy of the Australia-New Zealand trial of carvedilol in patients with heart failure due to ischemic heart disease, was to determine the effects of this treatment on left ventricular size and function with the use of quantitative two-dimensional (2D) echocardiography.

BACKGROUND

Beta-adrenergic blocking drugs have been shown to improve left ventricular ejection fraction in patients with heart failure due to either ischemic heart disease or idiopathic dilated cardiomyopathy. However, the effects of such treatment on left ventricular size remain uncertain.

METHODS

One hundred twenty-three patients from 10 centers in New Zealand and Australia participated in the 2D echocardiographic substudy. Echocardiography was performed before randomization and was repeated after 6 and 12 months of treatment. Left ventricular end-diastolic and end-systolic volumes were measured from apical four- and two-chamber views with the use of a modified Simpson's rule method.

RESULTS

After 12 months, heart rate was 8 beats/min lower in the carvedilol than in the placebo group, whereas left ventricular end-diastolic and end-systolic volumes were increased in the placebo group but reduced in the carvedilol group. At 12 months, left ventricular end-diastolic volume index was 14 ml/m2 less in the carvedilol than in the placebo group (p = 0.0015); left ventricular end-systolic volume index was 15.3 ml/m2 less (p = 0.0001), and left ventricular ejection fraction was 5.8% greater (p = 0.0015).

CONCLUSIONS

In patients with heart failure due to ischemic heart disease, carvedilol therapy for 12 months reduced left ventricular volumes, increased left ventricular ejection fraction and prevented progressive left ventricular dilation. These changes demonstrate a beneficial effect of carvedilol on left ventricular remodeling in heart failure. The observed changes may explain in part the improved clinical outcomes produced by treatment with carvedilol.

M-mode echocardiographic diagnosis of dilated cardiomyopathy in giant breed dogs

M-mode echocardiograms were recorded from 62 giant breed dogs without historical, clinical, electrocardiographic and roentgenologic signs of heart disease, from six dogs with asymptomatic dilated cardiomyopathy (DCM, NYHA class I), and 13 dogs with symptomatic DCM (NYHA class III-IV). There was a general trend that several echocardiographic parameters were significantly in control Great Danes as compared to Newfoundlands and Irish Wolfhounds. There were substantial differences in left ventricular size both in systole and diastole and in systolic indices of the left ventricle between the control group, the asymptomatic dogs and symptomatic dogs with DCM (P = 0.0001). There was also a significant decreased in the interventricular septum thickness (P = 0.0001) and left ventricular free wall thickness in systole (P = 0.002) and diastole (P = 0.005) between the three groups. Furthermore, the left atrial/aortic ratio was significantly different between the three groups (P = 0.0001). It was concluded that this study established echocardiographic reference values in giant breed dogs which may be useful in the study of heart diseases in giant breed dogs.

Discordance in degree of right and left ventricular dilation in patients with dilated cardiomyopathy: recognition and clinical implications

OBJECTIVES

The purpose of the present study was to assess the influence of variations in the relative degree of dilation of left and right ventricular chambers on the clinical outcome of patients with dilated cardiomyopathy.

BACKGROUND

Dilated cardiomyopathy, a primary myocardial disease characterized by ventricular dilation and systolic dysfunction, is generally associated with a poor prognosis. However, considerable variability has been observed in the clinical course and the morphologic and hemodynamic features in individual patients.

METHODS

We evaluated 67 consecutive patients with dilated cardiomyopathy and without evidence of ischemic or primary valvular heart disease. On the basis of diastolic ventricular chamber area measurements obtained by echocardiography, patients were classified into two groups: 38 patients with a relatively equal degree of left and right ventricular dilation (LV congruent to RV) and 29 patients with predominant and disproportionate dilation of the left ventricle (LV > RV).

RESULTS

The 67 patients ranged in age from 19 to 81 years (mean 56); 49 (73%) were male. The two subsets of patients with dilated cardiomyopathy did not differ with regard to age, left ventricular diastolic dimension, wall thickness and mass or ejection fraction. However, patients in the LV congruent to RV group showed more severe mitral and tricuspid regurgitation by Doppler echocardiography than did those in the LV > RV group (p = 0.01 for mitral and 0.004 for tricuspid regurgitation). Over the follow-up period of 2 to 60 months (mean 28), there were 19 deaths. Survival in the LV > RV group was significantly better than in the LV congruent to RV group (p = 0.03).

CONCLUSIONS

Patients with dilated cardiomyopathy represent a heterogeneous group with regard to both clinical outcome and the relative degree of left and right ventricular chamber dilation. Patients in the LV > RV subset appear to have better overall survival and less severe mitral and tricuspid regurgitation than do patients in the LV congruent to RV subset. Longitudinal studies are needed to determine whether these morphologic subsets in fact represent a continuum within the disease spectrum of dilated cardiomyopathy.

Prevalence and etiology of idiopathic dilated cardiomyopathy (summary of a National Heart, Lung, and Blood Institute workshop

Idiopathic dilated cardiomyopathy (IDC) is the primary indication for cardiac transplantation, with associated costs of approximately $177 million per year. Recognizing the economic implications of IDC, the increasing incidence, and the limited information on pathogenesis and prognosis, the National Heart, Lung, and Blood Institute convened a workshop on the Prevalence and Etiology of Idiopathic Dilated Cardiomyopathy on June 13 to 14, 1991. The difficulties of studying the disease were reviewed, including its relatively low prevalence, its potentially pluricausal nature, and the fact that it is often a diagnosis of exclusion. Still, it presents significant challenges to the cardiovascular scientific community, since the mechanism of myocardial damage and related etiologic and prognostic factors are virtually unknown. The development of more reliable measures of immune-mediated damage and noninvasive measures of impaired cardiac function present new research opportunities in this disorder. Standardized diagnostic criteria for use in observational and interventional trials were developed, and priorities for future research were proposed. Population-based registries and nested case-control studies, where feasible, are appropriate study designs for tracking incidence and prevalence, and for identifying risk factors, respectively. Interventional studies should focus on secondary prevention, through modifying immune-mediated damage in clinically evident dilated cardiomyopathy, and through prevention of sudden death in patients with the disorder. Primary prevention trials must await the identification of modifiable risk factors and of appropriate and effective interventions.

Left ventricular shape, afterload and survival in idiopathic dilated cardiomyopathy

Because idiopathic dilated cardiomyopathy is characterized by elevated wall stress and a more spherical left ventricle, the relations among shape, afterload and survival were examined. Thirty-six patients with cardiomyopathy were prospectively studied by two-dimensional echocardiography. Data included echocardiographic short- and long-axis cavity dimensions, their ratio and, with cuff systolic blood pressure, meridional and circumferential end-systolic stress and their ratios. Survivors (n = 16) were followed up for 52 months (range 40 to 76); nonsurvivors (n = 20) died an average of 11 months after study. Survivors had a smaller left ventricular end-diastolic short-axis dimension (6.4 versus 7.1 cm, p less than 0.03) but a similar long-axis length (8.6 versus 8.3 cm). However, overall cavity shape or the ratio of short- to long-axis end-diastolic dimensions was more spherical in those with poorer survival (ratio 0.76 versus 0.68, p less than 0.02). Meridional and circumferential end-systolic stresses were similar in the two groups, but stress was more evenly distributed in the long- and short-axis planes in nonsurvivors (meridional/circumferential stress ratio 0.57 versus 0.52 in survivors, p less than 0.05). Improved survival was associated with an end-diastolic short-axis dimension less than 7.63 cm, a short- to long-axis ratio less than 0.76 and a meridional to circumferential stress ratio less than 0.54. Life table analysis revealed a 28% mortality rate in patients with all three of these characteristics compared with 100% in patients with none. Survivors and nonsurvivors did not differ in systolic cavity dimension, wall thickness, relative wall thickness, cavity volume, percent posterior wall thickening or fractional shortening.(ABSTRACT TRUNCATED AT 250 WORDS)