Magnetic resonance imaging in familial hypertrophic cardiomyopathy associated with abnormal thallium perfusion and cardiac enzymes

Gated magnetic resonance imaging (MRI) was performed in 6 patients with familial hypertrophic cardiomyopathy associated with abnormal thallium perfusion, and 12 patients with ordinary hypertrophic cardiomyopathy. The patients with ordinary hypertrophic cardiomyopathy and abnormal thickening of the septal wall and normal left ventricular dimensions, while the patients with familial hypertrophic cardiomyopathy had focal wall thinning (usually involving the apical-septal wall) and dilated left ventricle in addition to hypertrophied heart. The quantitative measurement for cardiac dimensions using MRI was similar to that found on echocardiography in all cases. In addition, inhomogeneous signal intensities at left ventricular wall were observed in 3 cases of familial hypertrophic cardiomyopathy, which may suggest the existence of myocardial fibrosis. Gated MRI should be performed for early detection and follow-up of hypertrophic cardiomyopathy, since some patients will progress from hypertrophic cardiomyopathy to dilated cardiomyopathy.     

Left ventricular thrombosis is associated with increased mean platelet volume in patients with dilated cardiomyopathy and sinus rhythm

OBJECTIVE: Dilated cardiomyopathy has been associated with left ventricular thrombosis, which leads to substantial morbidity and mortality as a site for peripheral emboli. There are some studies on patients with dilated cardiomyopathy showing altered haemostasis and platelet behaviour despite sinus rhythm. Mean platelet volume, which is the most accurate and simple estimate of platelet reactivity, may be associated with the development of left ventricular thrombosis. METHODS AND RESULTS: We prospectively enrolled 48 consecutive patients with dilated cardiomyopathy and sinus rhythm with left ventricular thrombosis and compared them with an age-sex-matched control group having dilated cardiomyopathy without left ventricular thrombosis. We found that in patients with left ventricular thrombosis mean platelet volume is significantly higher than those without (9.5 +/- 0.8 vs. 8.7 +/- 0.6, p < 0.001). CONCLUSIONS: Mean platelet volume is increased in patients with dilated cardiomyopathy and sinus rhythm having left ventricular thrombosis. This might be reflecting a causal relationship, which in turn requires further study to establish the role of antiplatelet agents both in prevention and in treatment.     

Resting heart rate and cardiac function in dilated cardiomyopathy

We hypothesized that, within the normal range of resting heart rate, heart rate and left ventricular ejection fraction would be inversely correlated and heart rate and left ventricular filling would be correlated in patients with dilated cardiomyopathy and not correlated in patients with normal cardiac function. At rest, heart rate, left ventricular ejection fraction, and three measures of diastolic filling (time to peak filling rate, peak filling rate, and first half filling fraction) were recorded using radionuclide ventriculography in subjects with no cardiac disease, patients with idiopathic dilated cardiomyopathy, and patients with dilated cardiomyopathy associated with ischemic heart disease. Heart rate had significant inverse correlations with left ventricular ejection fraction (r=-0.55, P=0.0007) and time to peak filling rate (r=-0.47, P=0.005) and a positive correlation with peak filling rate (r=0.73, P<0.0001) in patients with idiopathic dilated cardiomyopathy; heart rate was correlated only weakly with these measures in the absence of cardiac disease and essentially was not correlated in dilated cardiomyopathy due to ischemic heart disease. The change in resting heart rate with left ventricular ejection fraction and time to peak filling rate were significantly (P<0.05) different between patients with no cardiac disease and those with idiopathic dilated cardiomyopathy. Thus, resting heart rate correlated significantly with left ventricular ejection fraction and diastolic filling in patients with idiopathic dilated cardiomyopathy.     

不同类型心肌病患者心脏超声特点差异性分析

目的分析不同类型心肌病患者心脏超声特点的差异。 方法将2017年1月至2018年9月在卫辉市人民医院就诊的55例扩张型心肌病患者(DCM组)和55例缺血性心肌病患者(ICM组)纳入研究,所有患者均接受超声心动图检查,对比两组患者LVEDD、LVESD、LAD、RAD、RVD、EF、FS、SV等超声心动图参数及心脏形态学改变情况。 结果ICM组患者LVEDD、LVESD、LAD、RAD、RVD、SV等指标水平均低于DCM组,EF、FS水平高于DCM组,差异有统计学意义(P<0.05);DCM组患者左心室"球"形样改变、室壁弥漫性运动减低发生率高于ICM组,左心室"圆拱门"形样改变、节段性室壁运动异常、左心室心尖圆而薄、主动脉根部钙化发生率低于ICM组,差异有统计学意义(P<0.05)。 结论DCM和ICM的超声心动图参数和心脏形态学变化存在较大差异,DCM患者多存在左右心室同时增大,而ICM患者主动脉瓣钙化较为严重。     

Does left ventricular shape influence clinical outcome in heart failure?

BACKGROUND: Left ventricular (LV) shape tends to become spherical in patients with dilated cardiomyopathy of diverse etiology. Clinical and echocardiographic factors which affect the degree of LV spherical distortion and the impact of altered LV shape on prognosis have not been studied adequately. HYPOTHESIS: This study was undertaken to investigate the prognostic implications of altered LV shape on clinical outcome in dilated cardiomyopathy. METHODS: In 112 patients with depressed LV ejection fraction (19 +/- 9%) and symptomatic heart failure, and in 10 age- and gender-matched normal controls, we performed 2-dimensional echocardiography to assess LV shape using the eccentricity index. Eccentricity index was defined as the ratio of the LV long axis to the LV transverse diameter, measured at end systole and end diastole in the apical four-chamber view. We sought univariate and multivariate clinical and echocardiographic correlates of LV shape. Further, we sought correlations between eccentricity index and clinical outcomes (death and composite outcome of death or emergent heart transplant). RESULTS: Compared with controls, patients with cardiomyopathy had significantly lower systolic (2.04 vs. 1.56; p = 0.001) and diastolic (1.75 vs. 1.53; p = 0.003) eccentricity index, implying a more spherical LV shape. Of all clinical and echocardiographic variables tested, mitral regurgitation, right ventricular dysfunction, and increased LV mass were independently associated with spherical LV shape. At a follow-up period of 17 +/- 12 months, no correlation was found between eccentricity index and the occurrence of death or the combined endpoint of death or emergent heart transplant, in univariate or multivariate analysis. CONCLUSIONS: In patients with dilated cardiomyopathy, the degree of spherical distortion of the LV does not correlate with prognosis.     

A case of cardiomyopathy induced by premature ventricular complexes.

Tachycardia-induced cardiomyopathy is a well-known and reversible condition, but the left ventricular dysfunction caused by frequent isolated premature ventricular complexes (PVCs) has been rarely reported. Apparent dilated cardiomyopathy was resolved in a patient after the focal source of PVCs was eliminated by radiofrequency catheter ablation. Echocardiography showed progressive improvement of the abnormal wall motion. Frequent PVCs could be the cause of left ventricular dysfunction in a subset of patients with dilated cardiomyopathy and radiofrequency ablation should be the choice of therapy in those patients.     

Evaluation of right ventricular function in patients with idiopathic dilated and ischemic cardiomyopathy by equilibrium radionuclide ventriculography

We performed equilibrium radionuclide ventriculography in 12 patients with idiopathic dilated cardiomyopathy, 11 patients with ischemic cardiomyopathy and 11 normal subjects to determine whether measurements of right ventricular function could be used to distinguish dilated cardiomyopathy from ischemic cardiomyopathy. The left ventricular ejection fraction in patients with dilated cardiomyopathy (26 +/- 8%, mean +/- SD) or ischemic cardiomyopathy (32 +/- 5%) was significantly lower than in normals (69 +/- 6%, p less than 0.001). The right ventricular ejection fraction (RVEF) in normals was 57 +/- 7%. RVEF was decreased in 11 of 12 patients with dilated cardiomyopathy and the mean value (32 +/- 10%) was significantly lower than that in patients with ischemic cardiomyopathy (56 +/- 7%, p less than 0.001), none of whom had decreased RVEF. Our data show that right ventricular dysfunction commonly exists in patients with dilated cardiomyopathy but not in patients with ischemic cardiomyopathy. This finding may be useful in the differentiation between dilated and ischemic cardiomyopathy.     

Relation between myocardial contractility,hypertrophy and pump performance in patients with chronic aortic regurgitation: an echocardiographic study

The aim of this study was to establish prognostic indices and to detect irreversible left ventricular dysfunction before aortic valve replacement in patients with chronic aortic regurgitation. Therefore, we determined the left ventricular pump/contractility relation (expressed as a ratio between ejection fraction and peak systolic pressure/end-systolic volume), afterload mismatch (the relation between the ejection fraction and mean systolic wall stress) and the left ventricular end-diastolic radius/posterior wall thickness ratio in 52 patients with chronic aortic regurgitation by means of M-mode echocardiography. These indices were also calculated in 14 patients with idiopathic dilated cardiomyopathy and in 20 normal controls. The indices allowed separation of normals and patients with mild to moderate aortic insufficiency from patients with idiopathic dilated cardiomyopathy indicating that these indices could distinguish between patients with a reversible afterload mismatch and those with irreversible impaired muscle function. The 38 patients with severe aortic insufficiency showed a large overlap between normal and abnormal indices. Twelve of these patients had a pump/contractility index and a ratio between ejection fraction and wall stress similar to that found in patients with idiopathic dilated cardiomyopathy. All these patients, however, had a left ventricular end-diastolic radius/thickness ratio > 4 indicating “inadequate hypertrophy”. Of these, 3 patients died perioperatively and 4 developed congestive heart failure within 12 months postoperatively.We conclude that an end-diastolic radius/thickness ratio > 4 is a sensitive but not a specific preoperative indicator of irreversible left ventricular damage in patients with chronic aortic regurgitation. This index is readily obtained preoperatively by M-mode echocardiography.     

Histopathologic changes in asymptomatic relatives of patients with idiopathic dilated cardiomyopathy

Echocardiographic screening of asymptomatic relatives of patients with idiopathic dilated cardiomyopathy identifies a subset with left ventricular enlargement who are assumed to have early familial idiopathic dilated cardiomyopathy. This study shows for the first time that the myocardium in such relatives demonstrates abnormal cellularity.     

Cardiac manifestations in disorders of fat and carnitine metabolism in infancy

The prognosis of patients with cardiomyopathy associated with hypocarnitinemia is uncertain. Cardiac hemodynamics, histologic findings and response to oral L-carnitine therapy were retrospectively evaluated in 11 children with cardiomyopathy associated with abnormal carnitine metabolism. Three had systemic carnitine deficiency, two familial hypocarnitinemia with neutropenia, three transient neonatal hypocarnitinemia and three a carnitine insufficiency syndrome. Six had a hypertrophic and five a dilated cardiomyopathy. Hypotonia was present in seven (64%). The cardiothoracic ratio was greater than 0.60 in eight (73%). The most frequent abnormality on the electrocardiogram was ST-T wave inversion in the left precordial leads with various degrees of left ventricular hypertrophy. Echocardiographically, two patients with hypertrophic cardiomyopathy had decreased left ventricular function and two patients with dilated cardiomyopathy had increased thickness of the left ventricular wall. Histologic evaluation (two autopsies and one endomyocardial biopsy) revealed striking lipid accumulation within hypertrophied myocytes. Six of eight patients on carnitine replacement therapy had improvement echocardiographically during a 3 month to 2 year follow-up period. In summary, both hypertrophic and dilated cardiomyopathy can result from abnormal carnitine metabolism. The determination of plasma carnitine concentrations and fatty acid metabolism by-products should be performed in all patients with either form of cardiomyopathy of unknown etiology because carnitine supplementation may lead to improvement.     

Mechanism of Mitral Regurgitation in Dilated Cardiomyopathy

Dilated cardiomyopathy is a condition characterized by chamber dilatation and impaired systolic function, resulting in the clinical manifestations of congestive heart failure. Mitral regurgitation occurs with varying frequency in dilated cardiomyopathy, and its detection depends on the diagnostic modality utilized. The presence of mitral regurgitation imposes an additional burden on the failing ventricle, and appears to be an independent prognostic indicator of mortality. The mechanism of mitral regurgitation in dilated cardiomyopathy is complex, controversial, and incompletely understood. The mitral apparatus consists of the left atrial wall, mitral annulus, mitral leaflets, chordae tendineae, papillary muscles, and left ventricular wall, and each of these components and the intimate interrelationship between these structures may contribute to the development of mitral regurgitation. Left atrial enlargement, reduced left atrial contractility, mitral leaflet retraction, abnormal vector of chordal tendineae pull, papillary muscle dysfunction (either asynergic contraction or malalignment), mitral annular dilatation, and changes in the size, shape, and function of the left ventricle have been suggested as possible mechanisms for the development of mitral regurgitation in dilated cardiomyopathy. The primary event in the development of mitral regurgitation appears to be left ventricular dilatation and dysfunction. Controversy persists as to whether the associated mechanism is annular dilatation, papillary muscle or free left ventricular wall dysfunction, or a combination of all, but recent echo-Doppler studies reviewed in this article support the notion that annular dilatation is the predominant mechanism. Improved understanding of the mechanism of mitral regurgitation in dilated cardiomyopathy may lead to a more aggressive approach with regard to pharmacological therapy, thus impacting on survival in this group of patients. (ECHOCARDIOGRAPHY, Volume 8, March 1991)     

Activity of cAMP-dependent protein kinase and Ca2+/calmodulin-dependent protein kinase in failing and nonfailing human hearts.

OBJECTIVES: A hallmark of human heart failure is prolonged myocardial relaxation. Although the intrinsic mechanism of phospholamban coupling to the Ca(2+)-ATPase is unaltered in normal and failed human hearts, it remains possible that regulation of phospholamban phosphorylation by cAMP-dependent mechanisms or other second messenger pathways could be perturbed, which may account partially for the observed dysfunctions of the sarcoplasmic reticulum (SR) associated with this disease. METHODS: cAMP-dependent protein kinase (PKA) and Ca2+/calmodulin-dependent protein kinase II (CaM kinase) were characterized initially by DEAE-Sepharose chromatography in hearts from patients with end-stage dilated cardiomyopathy. We measured the activity of PKA and CaM kinase in left ventricular tissue of failing (idiopathic dilated cardiomyopathy; ischemic heart disease) and nonfailing human hearts. RESULTS: Basal PKA activity was not changed between failing and nonfailing hearts. One major peak of CaM kinase activity was detected by DEAE-Sepharose chromatography. CaM kinase activity was increased almost 3-fold in idiopathic dilated cardiomyopathy. In addition, hemodynamical data (left ventricular ejection fraction, cardiac index) from patients suffering from IDC positively correlate with CaM kinase activity. CONCLUSIONS: Increased CaM kinase activity in hearts from patients with dilated cardiomyopathy could play a role in the abnormal Ca2+ handling of the SR and heart muscle cell.     

组织多普勒技术评价扩张型心肌病左室心功能的临床价值

目的探讨组织多普勒技术(TDI)检测扩张型心肌病(DCM)左室心功能的临床价值。方法选择DCM病人和正常健康者各40例,用TDI于胸骨旁长轴检测室间隔及左室后壁中间段短轴方向心肌运动速度(MV),并计算心肌运动速度阶差(MVG);经心尖窗检测左室前壁、后壁、下壁、侧壁和前壁、后壁室间隔中间段长轴方向MV。结果DCM组病人出现4种MV频谱形态异常,长轴、短轴方向MV均明显低于正常对照组(P<0.05或P<0.01);DCM组MVG也明显低于正常对照组(P<0.05或P<0.01)。结论TDI可定量评价DCM病人左室心肌功能,丰富了DCM的超声诊断手段。     

Ventricular thrombi and thromboembolism in dilated cardiomyopathy: a prospective follow-up study.

To determine the prevalence and natural history of left ventricular thrombus in dilated cardiomyopathy, we prospectively performed two-dimensional echocardiograms in 25 patients with nonischemic dilated cardiomyopathy who were not receiving anticoagulation. Eighty-five echocardiograms were performed serially over a 9- to 30-month period (mean follow-up 21.5 months). A left ventricular thrombus was present on initial echocardiogram in 11 (44%) patients, became present during follow-up in an additional four, and disappeared in two. Thrombus was significantly more common in patients with fractional shortening of less than or equal to 10% (12 of 15) than in those with a fractional shortening 11% to 25% (3 of 10) (p less than 0.02). Five embolic events (four cerebral) occurred over the follow-up period, four of which were associated with a previously visualized left ventricular thrombus. Three of five thrombi that protruded into the left ventricular cavity subsequently embolized. We conclude that in nonanticoagulated patients with dilated cardiomyopathy left ventricular thrombus and thromboembolism are common. Echocardiography may be helpful in predicting which patients are at risk of thromboembolism.     

Interstudy reproducibility of dimensional and functional measurements between cine magnetic resonance studies in the morphologically abnormal left ventricle

The validity of geometric formulas to derive mass and volumes in the morphologically abnormal left ventricle is problematic. Imaging techniques that are tomographic and therefore inherently three-dimensional should be more reliable and reproducible between studies in such ventricles. Determination of reproducibility between studies is essential to define the limits of an imaging technique for evaluating the response to therapy. Sequential cine magnetic resonance (MR) studies were performed on patients with dilated cardiomyopathy (n = 11) and left ventricular hypertrophy (n = 8) within a short interval in order to assess interstudy reproducibility. Left ventricular mass, volumes, ejection fraction, and end-systolic wall stress were determined by two independent observers. Between studies, left ventricular mass was highly reproducible for hypertrophied and dilated ventricles, with percent variability less than 6%. Ejection fraction and end-diastolic volume showed close reproducibility between studies, with percent variability less than 5% End-systolic volume varied by 4.3% and 4.5% in dilated cardiomyopathy and 8.4% and 7.2% in left ventricular hypertrophy for the two observers. End-systolic wall stress, which is derived from multiple measurements, varied the greatest, with percent variability of 17.2% and 15.7% in dilated cardiomyopathy and 14.8% and 13% in left ventricular hypertrophy, respectively. The results of this study demonstrate that mass, volume, and functional measurements are reproducible in morphologically abnormal ventricles.     

First evidence of premature ventricular complex-induced cardiomyopathy: a potentially reversible cause of heart failure

Tachycardia-induced cardiomyopathy is a well-recognized and reversible condition, but left ventricular dysfunction due to frequent isolated premature ventricular complexes (PVCs) has not been reported. We observed resolution of dilated cardiomyopathy in a patient after a focal source of PVCs was eliminated by radiofrequency ablation. In a subset of patients with heart failure, PVC-induced cardiomyopathy may be a potentially reversible cause of left ventricular dysfunction.     

Diagnosis of anomalous left coronary artery by Doppler color flow mapping: distinction from other causes of dilated cardiomyopathy.

BACKGROUND. Anomalous origin of the left coronary artery from the pulmonary trunk is difficult to diagnose reliably by two-dimensional echocardiography. Therefore, Doppler color flow mapping was tested in 29 patients with dilated cardiomyopathy or anomalous left coronary artery, or both. METHODS AND RESULTS. All patients with anomalous left coronary artery (10 patients) or dilated cardiomyopathy (27 patients) (excluding those with other known causes for cardiomyopathy) examined between January 1988 and May 1991 were identified. The direction of flow in the three main segments of the left coronary system was determined by Doppler color flow mapping. In all 10 patients with anomalous left coronary artery, flow mapping demonstrated an abnormal jet from the left coronary artery into the pulmonary trunk and retrograde flow in at least two segments of the left coronary system. The diagnosis was confirmed in all 10 patients at operation. Doppler color flow mapping, performed in 19 of the 27 patients with dilated cardiomyopathy, demonstrated anterograde flow in at least one segment of the left coronary system in 16 of the 19 patients; flow direction was not determined in the other 3 patients. Coronary artery anatomy was confirmed by aortic root or left ventricular angiography in 14 patients and at autopsy in 1 patient and was not directly confirmed in 4 patients. Left ventricular function spontaneously improved to normal in three of the latter four patients, a clinical course not consistent with anomalous left coronary artery. The left coronary artery appeared to arise from the aortic root by two-dimensional echocardiographic imaging alone in all patients with dilated cardiomyopathy and in 5 of 10 patients with anomalous left coronary artery (50% false negative diagnoses). CONCLUSIONS. Detection of an abnormal jet into the pulmonary trunk and retrograde flow in the left coronary system by Doppler color flow mapping is reliable for diagnosing anomalous left coronary artery whereas two-dimensional echocardiographic imaging alone is often inconclusive or misleading. Determining flow direction in the left coronary system in patients with dilated cardiomyopathy is useful for excluding anomalous left coronary artery but is technically more difficult to document in this condition than in anomalous left coronary artery.     

The coagulation system is activated in idiopathic cardiomyopathy

Objectives. We investigated the plasma levels of molecular markers for platelet activity and the thrombotic and fibrinolytic status in patients with hypertrophic cardiomyopathy and dilated cardiomyopathy to determine the activating site of coagulation in these disorders.

Background. A thromboembolic event is a serious complication in patients with idiopathic cardiomyopathy. However, the activating site of the coagulation system in idiopathic cardiomyopathy has not been fully investigated.

Methods. We determined the plasma levels of molecular markers for platelet activity (platelet factor 4 and beta-thromboglobulin), thrombotic status (fibrinopeptide A and thrombin-antithrombin III complex) and fibrinolytic status (D-dimer and plasmin-alpha₂-plasmin inhibitor complex) in 13 patients with hypertrophic cardiomyopathy, 17 patients with dilated cardiomyopathy and 20 normal subjects.

Results. Plasma levels of platelet factor 4, beta-thromboglobulin and plasmin-alpha₂-plasmin inhibitor complex did not differ significantly among the three groups, whereas plasma levels of fibrinopeptide A and thrombin-antithrombin III complex in both patient groups were significantly higher than those in normal subjects. Plasma levels of D-dimer in patients with dilated cardiomyopathy were significantly higher than those in patients with hypertrophic cardiomyopathy and normal groups. In patients with hypertrophic cardiomyopathy, both fibrinopeptide A and thrombin-antithrombin III complex levels were significantly correlated with left atrial diameter. In patients with dilated cardiomyopathy, fibrinopeptide A and thrombin-antithrombin III complex levels showed a positive correlation with left ventricular end-diastolic volume and a negative correlation with fractional shortening of the left ventricle.

Conclusions. The activated coagulation system in patients with hypertrophic and dilated cardiomyopathy may be triggered by left atrial dilation in hypertrophic cardiomyopathy and left ventricular enlargement and dysfunction in dilated cardiomyopathy.     

Lymphocyte subsets in patients with acute myopericarditis, arrhythmias and dilated cardiomyopathy

To investigate the role of immunoregulatory function in determining the clinical course of acute myopericarditis, lymphocyte subsets were analysed by laser flow cytometry in 20 patients with acute myopericarditis, 30 with various arrhythmias or atrio-ventricular block and 31 with dilated cardiomyopathy. During the healing stage of acute myopericarditis, patients with residual electrocardiographic or left ventricular wall motion abnormalities presented altered frequencies of lymphocyte subsets, increased B 1 and reduced OKT 8 positive cells with an elevated OKT 4/8 ratio. The abnormal pattern was not evident in patients with acute pericarditis nor in those with acute myocarditis who recovered completely without residual abnormalities. This observation suggested that an imbalance of helper/suppressor T cells could modulate the clinical course of acute myopericarditis, either by producing extensive and irreversible myocardial damage during acute illness or by inducing chronic smoulding myocardial inflammation. Patients with ventricular arrhythmias and left ventricular wall motion abnormalities also presented reduced suppressor/cytotoxic T cells, implying that they had been suffering from chronic smoulding myocarditis mediated by immunoregulatory dysfunction. However, we could not determine whether the imbalance of helper/suppressor T cells could mediate the progression from myocarditis to dilated cardiomyopathy, since no association was demonstrated between the abnormal lymphocyte subsets and mononuclear cell infiltration in endomyocardial biopsy sample from patients with dilated cardiomyopathy.     

Antimyosin antibody cardiac imaging: its role in the diagnosis of myocarditis

Right ventricular endomyocardial biopsy currently remains the procedure of choice for identifying patients with symptomatic heart failure due to myocarditis from the larger population with idiopathic dilated cardiomyopathy. Despite its specificity, the sensitivity of right ventricular biopsy remains uncertain because of the focal or multifocal nature of the disease. Because myocyte necrosis is an obligate component of myocarditis, the use of indium-111 antimyosin imaging was evaluated in 82 patients with suspected myocarditis. Seventy-four patients had dilated cardiomyopathy of less than 1 year's duration (mean left ventricular ejection fraction 0.30 +/- 0.02); eight patients had normal left ventricular function (mean ejection fraction 0.59 +/- 0.03). Symptoms at presentation included congestive heart failure (92%), chest pain mimicking myocardial infarction (6%) and life-threatening ventricular tachyarrhythmias (2%). All patients underwent planar and single photon emission computed tomographic (SPECT) cardiac imaging after injection of indium-111-labeled antimyosin antibody fragments and right ventricular biopsy within 48 h of imaging. Antimyosin images were interpreted as either abnormal or normal and correlated with biopsy results. On the basis of the right ventricular histologic examination, the sensitivity of antimyosin imaging was 83%, specificity 53% and predictive value of a normal scan 92%. Improvement in left ventricular function occurred within 6 months of treatment in 54% of patients with an abnormal antimyosin scan compared with 18% of those with a normal scan (p less than 0.01). Antimyosin cardiac imaging may be useful for the initial evaluation of patients with dilated and nondilated cardiomyopathy and clinically suspected myocarditis.(ABSTRACT TRUNCATED AT 250 WORDS)