Hypertrophic cardiomyopathy simulating an infiltrative myocardial disease.

Congestive heart failure developed in a patient with low electrocardiographic QRS voltages, diffuse thickening of the septum and free cardiac wall, and a reduction in left ventricular internal diameter, which suggested an infiltrative heart muscle disease. Histological examination at necropsy showed hypertrophic cardiomyopathy with symmetrical left ventricular hypertrophy. Myocardial disarray of type 1A disorganisation was extensive and equally distributed in the ventricular septum and the left anterior and left posterior ventricular free walls. Severe fibrosis (40%) was also present and may have been a possible cause of the electrocardiographic abnormalities as well as of the lack of ventricular dilatation.     

Evolving electrocardiographic changes in massive neoplastic infiltration of the right ventricle. Description of a case and review of the literature

We report a case of metastasis of lung carcinoma infiltrating the inferior left ventricular wall, the interventricular septum and the right ventricle. The metastatic invasion of the heart caused the appearance of pseudoischemic electrocardiographic changes, arrhythmias and eventually a conduction disturbances. The relevance of electrocardiographic changes as an indicator of cardiac metastasis in neoplastic patients is discussed.     

Computer model study of electrocardiologic manifestations in asymmetric left ventricular hypertrophy

Electrocardiologic criteria of left ventricular enlargement do not take into consideration the eventuality of asymmetric hypertrophy. Since experimental techniques for production of this condition are not available, computer modeling was utilized to study its electrocardiologic manifestations. A computer model of human ventricles with analytically defined geometry, consisting of 142 000 elements (1.2 mm spatial resolution), was used to produce models of circumscribed hypertrophies by increasing the wall thickness to 150% in various regions of the free left ventricular wall, the septum and the apex. Gradients of simulated transmembrane action potentials were utilized to compute resultant heart vectors at any instant of ventricular activation and recovery, as well as time courses of their characteristics and planar projections of vectorgraphic loops. Involvement of the septum and/or the anterior wall decreased the maximum QRS vector magnitude, an opposite effect resulted from involvement of the lateral and posterior wall segments. Directional vector changes predicted the diagnostic value of S waves in precordial leads. Asymmetric hypertrophy did not produce abnormal Q waves. The maximum T vector increased in hypertrophy of any part of the free wall along with an increase of the spatial angle between maximum QRS and T vectors. The results of this study may be useful for refinement of electrocardiographic and vectorcardiographic diagnostic criteria of asymmetric left ventricular hypertrophy.     

Echocardiographic study of hypertrophic cardiomyopathy localized in the free wall of the left ventricle

Previous studies have shown that the Hypertrophic Cardiomyopathy may involve the left ventricle free wall, without involving the intraventricular septum. We describe two young sisters who were suspected of having Hypertrophic Cardiomyopathy because of their family history and because of abnormal electrocardiographic findings. M-mode echocardiography showed normal ventricular septal thickness, increased thickness of the left ventricular posterior wall, decreased diastolic posterior wall velocity, normal left ventricular outflow tract. Two-dimensional echocardiography showed that hypertrophy was limited to left ventricular free wall, especially to the lateral and anterior segments. Echocardiography can thus identify unusual forms of hypertrophic cardiomyopathy.     

Electrocardiogram during cardiac ruture by myocardial infarction

In 100 patients with acute myocardial infarction the electrocardiogram was continuously registered during 72 hours. Nine patients died of ventricular rupture (eight of the left ventricular free wall and one of the ventricular septum). In eight cases death occurred while the electrocardiogram was being recorded. A specific pattern of electrocardiographic changes seems to occur during acute tamponade, i.e. slowing of sinus rhythm followed by nodal rhythm.     

Electrocardiogram during cardiac rupture by myocardial infarction

In 100 patients with acute myocardial infarction the electrocardiogram was continuously registered during 72 hours. Nine patients died of ventricular rupture (eight of the left ventricular free wall and one of the ventricular septum). In eight cases death occurred while the electrocardiogram was being recorded. A specific pattern of electrocardiographic changes seems to occur during acute tamponade, i.e. slowing of sinus rhythm followed by nodal rhythm.     

Asymmetric septal hypertrophy in a 41-year-old woman with Noonan's syndrome

A 41-year-old woman had Noonan's syndrome. Her heart was complicated by asymmetric septal hypertrophy, hypertrophy of the left ventricular free wall, severe pulmonary stenosis, and right ventricular hypertension. On autopsy, a quantitative histologic analysis of the heart revealed that the area of disarray was limited both to the ventricular septum and the left ventricular free wall as in a normal heart. This is not typical of hypertrophic cardiomyopathy because the extent of disarray is high in most cases of hypertrophic cardiomyopathy. Some form of hypertrophic cardiomyopathy, however, seemed to be present in this patient because right ventricular pressure overload did not affect the left ventricular free wall. To clarify the relation between hypertrophic cardiomyopathy and Noonan's syndrome, quantitative histologic analysis is necessary.     

Tissue Doppler assessment of longitudinal right and left ventricular strain and strain rate in pulmonary artery hypertension

Tissue Doppler imaging (TDI) in 38 adult patients with pulmonary artery hypertension of varied etiology and normal left ventricular systolic function by two-dimensional transthoracic echocardiography showed significantly reduced peak systolic strain (SS) in all three segments of left ventricular free wall and ventricular septum and two of three segments of right ventricular free wall when compared to 29 adults with no clinical or echocardiographic evidence of heart disease and normal left and right ventricular systolic function. A similar reduction in peak diastolic strain (DS) was also noted in all three segments of left ventricular free wall and ventricular septum and one of three segments of right ventricular free wall. This reduction in strain indices in patients with pulmonary hypertension was noted irrespective of whether right ventricular systolic function was normal or reduced as assessed by two-dimensional transthoracic echocardiography. SS and DS rates also showed reductions in patients with pulmonary artery hypertension. Our study shows the potential value of TDI indices in identifying reduced regional left ventricular systolic and diastolic longitudinal function in patients with pulmonary artery hypertension and normal left ventricular systolic function by two-dimensional transthoracic echocardiography. This reduction in left ventricular function was noted in patients with both normal and reduced right ventricular systolic functions by two-dimensional echocardiography.     

Roles of the right ventricular free wall and ventricular septum in right ventricular performance and influence of the parietal pericardium during right ventricular failure in dogs

The roles of the right ventricular (RV) free wall and ventricular septum in RV performance were studied in the canine heart. The parietal pericardium was kept intact. Acute ischemia of the RV free wall from right coronary ligation decreased the RV stroke work index more than did that of the ventricular septum from the septal branch of the left coronary artery ligation (41 and 23%, respectively, p < 0.01). The response of the RV stroke work index to acute volume loading was also decreased. Left ventricular dysfunction was detected only with ventricular septal ischemia. Combined RV free wall and ventricular septal ischemia produced more severe and predominant RV dysfunction with disproportionate elevation of RV end-diastolic pressure. After combined ischemia, pericardiotomy improved the RV stroke work index as well as the left ventricular stroke work index (40 and 27%, respectively, p < 0.05), although the increase in RV stroke work index was greater than in left ventricular stroke work index (p < 0.05).The results of this study suggest that (1) the RV free wall has a more important role than the ventricular septum in RV performance, (2) predominant RV failure can be induced experimentally after combined RV free wall and ventricular septal ischemia, and (3) the pericardium has a restrictive effect on the damaged and dilated right ventricle.     

Scoring technique for diagnosis of ventricular hypertrophy from three orthogonal lead electrocardiogram.

A prospective study for the development of scoring techniques for the diagnosis of ventricular hypertrophy from the three orthogonal lead electrocardiogram was undertaken. A total of 51 hearts was examined at necropsy in a training group on which the scoring techniques were developed and a test group of a further 82 hearts was studied to assess the sensitivity and specificity of the method. The hearts were classified as being normal or having left ventricular hypertrophy, right ventricular hypertrophy, biventricular hypertrophy, or were placed in a borderline category. These classifications were based on the measurement of the weight of the left ventricular free wall, the interventricular septum, and the right ventricular free wall. Classical electrocardiographic variables were selected and assigned a point score on the basis of their diagnostic value. The electrocardiographic diagnosis of left ventricular hypertrophy, right ventricular hypertrophy, and biventricular hypertrophy was then made when the relevant score exceeded four points. After excluding 25 cases which showed conduction defects or were regarded as borderline at necropsy, 57 cases remained in the test group for assessing the technique. The sensitivity and specificity for left ventricular hypertrophy were 65 per cent and 91 per cent, respectively. For right ventricular hypertrophy corresponding results were 53 and 90 per cent. For biventricular hypertrophy the sensitivity was lower at 42 per cent, with a corresponding specificity of 93 per cent. These results represent a considerable improvement over older techniques, with up to a tenfold increase in sensitivity being obtained. The technique can be applied with or without computer assistance.     

Echocardiographic findings in Pompe's disease with left ventricular obstruction

Two infants with Pompe's disease (type II glycogenosis) showing echocardiographic evidence of obstructive cardiomyopathy are described. On M-mode and two-dimensional (2-D) echocardiography there was a severe hypertrophy of the interventricular septum, free, and posterior left ventricular wall with midsystolic closure of the aortic valve. The combined echocardiographic and electrocardiographic findings are helpful in the clinical diagnosis of this severe disease.     

Myocardial fiber diameter and regional distribution in the ventricular wall of normal adult hearts, hypertensive hearts and hearts with hypertrophic cardiomyopathy

Myocardial fiber diameters were measured to determine their distribution throughout the ventricular wall in normal adult hearts, hypertensive hearts and hearts with hypertrophic cardiomyopathy (HCM). In normal adult hearts and hypertensive hearts, the diameter decreased from the inner to the outer third of the left ventricular free wall and from the left ventricular side to the right ventricular side of the septum. In HCM, these regional differences were preserved in the left ventricular free wall, but not in the septum. The diameter was greatest in the middle third of the septum, where myocardial fiber disarray was widely distributed. The diameters of the fibers in the right ventricular side of the septum were significantly larger than those of the fibers in the left ventricular side of the septum in HCM. This finding, in contrast to that in normal adult hearts or hypertensive hearts, was considered to be related to the inward convex curvature of the left ventricular chamber. Although there was no significant difference in the diameter of myocardial fibers in the left ventricular free wall between hypertensive hearts and hearts with HCM, the diameters of those in the right ventricular free wall, in the right ventricular side of the septum and in the middle third of the septum were significantly larger in HCM than in hypertensive hearts. We conclude that there is a transmural variation of myocardial fiber diameter in the left ventricular free wall and the ventricular septum, and such transmural variation in HCM is clearly different from that in hypertensive hearts.     

Electrocardiographic findings in single ventricle and related conditions

A review is made of the electrocardiographic findings of 33 cases with derangement in the spatial relationship between the ventricular septum and the atrioventricular canal.To obtain an analysis with a maximal homogeneity, six groups are established according to the extent and direction of the above-mentioned derangement (Table I). Groups IA and IIA are equivalent to the most frequent designations of single left and right ventricle, respectively, or more exactly, to those of double-inlet left and right ventricle.Cases with disturbance in the position of the heart are considered separately to ascertain whether the outflow obstructions and the bulboventricular loop influence the electrocardiographic morphologies in any way.Electrocardiographic features of the other four groups (Table I) are analyzed to determine if the differences in the relationship between the atrioventricular canal and the interventricular septum are of small degree, and therefore if the hypoplastic cavity becomes larger.     

Frequency and location of prominent left ventricular trabeculations at autopsy in 474 normal human hearts: implications for evaluation of mural thrombi by two-dimensional echocardiography

The frequency and location of prominent left ventricular trabeculations were studied in 474 autopsy specimens from subjects evenly distributed by sex and age. These structures were observed in 323 (68%) of the hearts, and their frequency was similar in male (72%) and female (65%) subjects. Neither the frequency nor the location varied appreciably with age. Among the 323 hearts with prominent left ventricular trabeculations, 172 (53%) exhibited 2 or more; thus, the total number of trabeculations was 582. Of these 582 trabeculations, 493 (85%) were septoparietal bundles that inserted into both the free wall and the septum. Trabeculations also were observed between two points on the ventricular septum in 37 (6%) of the hearts and between two points along the free wall in 36 (6%). Less common patterns included trabeculations between the ventricular septum and the posteromedial papillary muscle in 10 hearts (2%), the ventricular septum and the anterolateral papillary muscle in 2, the free wall and the posteromedial papillary muscle in 2, the two papillary muscles in 1 and the apex and the ventricular septum in 1. Accordingly, prominent left ventricular trabeculations are considered to be common variants of the normal human heart. Their size, shape and location may lead to their being misinterpreted, possibly as mural thrombi, by two-dimensional echocardiography.     

Can the site of origin of ventricular extrasystoles enhance the localisation of exercise-induced ischaemia?

Previous work from the Departments of Cardiology and Nuclear Medicine, Guy's Hospital, London, has enabled an atlas of the electrocardiographic appearances of ectopics from individual ventricular sites to be compiled. This has been used to investigate the relationship between regions of myocardial ischaemia and the site of origin of exercise-induced ventricular arrhythmias. Two hundred and ten patients underwent maximal exercise testing on a bicycle ergometer, prior to thallium scintigraphy. All 12 leads of the electrocardiogram were recorded simultaneously at rest, immediately post-exercise and then for several minutes afterwards. Thallium scintigraphy was performed immediately and 4 hours post-exercise. Twenty-nine patients of the 210 had ventricular arrhythmias on exercise. Two had dilated (congestive) cardiomyopathy, 1 had hypertrophic cardiomyopathy and 26 were subsequently proven to have ischaemic heart disease. Fifteen of those patients with coronary artery disease and ventricular arrhythmias had otherwise negative exercise tests. Patients with reversible posterior (circumflex) defects had right bundle branch block extrasystoles with a limb lead QRS axis of -60 degrees to -150 degrees. Reversible inferior defects demonstrated ectopic activity with left bundle branch block and a superior axis. Ectopics of septal origin could present with either right or left bundle branch block and an inferior axis from the upper septum, or superior axis from the lower septum. In patients with ischaemic heart disease the 12-lead electrocardiographic appearance of ventricular arrhythmias enables their site of origin to be localised thus suggesting ischaemia in a particular coronary artery territory.     

Influence of acute mechanical overload on dimension and dynamics of interventricular septal thickness in dogs

To evaluate directly septal thickness and related dynamic changes, miniature ultrasonic crystals were Implanted across the Interventricular septum and left ventricular free wall and In the circumferential endocanNal segments of the left and right ventricles In 12 open chest dogs. In the control resting state, end-dlastollc wall thickness of the septum and the left ventricular free wall was 9.4 ± 2.1 and 9.6 ± 2.6 mm, respectively (mean ± standard deviation). Wall thickness Increased during systole by 15 percent In the septum and by 17 percent in the free wall. With constriction of the ascending aorta, left ventricular end-dlastollc segment Increased by 13 percent with reciprocal thinning In the end-dlaslollc thickness of the septum (by ?8.5 percent) and the left ventricular free wall (by ?5.2 percent); there were decreases in percent shortening of the left ventricular segment (from 21.0 to 15.5 percent) and In percent thickening of both the septum (from 14.6 to 11.8 percent) and the free wall (from 16.9 to 13.1 percent).Pulmonary arterial constriction resulted In significant right ventricular chamber enlargement; however, there was no direct change In dimension and dynamics of the septum. When mitral regurgitation was produced by sectioning the chordae tendlneae, left ventricular end-dlastollc segment length Increased (by 23.5 percent) with reciprocal thinning of the enddlastollc thickness of the septum (by ?8.6 percent) and the free wall (by ?6.9 percent). The left ventricular segment shortening and wall thickening of the septum and the free wall were equally augmented (from 18.6 to 37.5, from 16.1 to 31.0 and from 19.8 to 29.3 percent, respectively). Wtth the onset of acute tricuspld regurgitation, right ventricular end-dlastollc segment and its shortening Increased markedly, but there were no direct changes in the septum. Thus, the interventrlcular septum can be regarded as a functional part of the left ventricle, and any form of mechanical loading on the left ventricle will ultimately Induce proportionate changes in the septum and left ventricular free wall.     

Incessant ventricular tachycardia in infants: myocardial hamartomas and surgical cure

Infants with incessant ventricular tachycardia (occurring greater than 10% of the day) have generally been described in pathologic studies. This report describes 21 patients with incessant ventricular tachycardia present greater than 90% of the day and night; the age at diagnosis ranged from birth to 30 months (mean 10.5 months). The most common clinical presentation was cardiac arrest (11 patients, in 5 after digitalis for presumed supraventricular tachycardia); another 6 patients had congestive heart failure and 4 were asymptomatic. Three patients had coexisting Wolff-Parkinson-White syndrome. The rate of incessant ventricular tachycardia ranged from 167 to 440 (mean 260 beats/min) and the QRS duration from 0.06 to 0.11 second. The most common electrocardiographic (ECG) pattern (10 of 21) was right bundle branch block with left axis deviation, but other right and left bundle branch block patterns were observed. Conventional and investigational antiarrhythmic agents (nine patients received amiodarone) failed to eliminate incessant ventricular tachycardia in all. Electrophysiologic studies localized incessant ventricular tachycardia to the left ventricle in 17 (to the apex in 2, the free wall in 9 and the septum in 6) and to the right ventricular septum in 4. No structural abnormalities were found on the echocardiogram or angiocardiogram. All 21 patients had surgery at an age of 3.5 to 31 months (mean 16). In 15 a tumor was found: 13 myocardial hamartomas (9 discrete, 4 diffuse throughout both ventricles) and 2 rhabdomyomas (1 multiple). Myocarditis was found in one patient (the oldest). In four, only myocardial fibrosis was found; results of one biopsy were normal.(ABSTRACT TRUNCATED AT 250 WORDS)     

Right ventricular dyssynchrony in heart failure: a tissue Doppler imaging study

BackgroundThe development of right ventricular dysfunction is a poor prognostic sign in patients with heart failure (HF). Although left ventricular dyssynchrony has been well described, it is not known whether right ventricular dyssynchrony coexists in HF. We used tissue Doppler imaging to determine whether right ventricular dyssynchrony is also present in HF patients.Methods and ResultsIn 34 HF patients (mean age 56 ± 13 years), we measured longitudinal strain at the right ventricular free wall, interventricular septum, and left ventricular lateral wall. Right ventricular and left ventricular dyssynchrony were defined as the difference in time to peak strain between the right ventricular free wall and the septum and between the left ventricular lateral wall and septum, respectively. Mean right ventricular dyssynchrony was 59 ± 45 ms and the mean left ventricular dyssynchrony was 80 ± 62 ms. We found a strong correlation between right ventricular dyssynchrony and pulmonary artery systolic pressure (r = 0.73; P < .001) and a negative correlation between right ventricular dyssynchrony and right ventricular fractional area change (r = −0.43; P < .02).ConclusionHF patients exhibit right ventricular dyssynchrony by strain imaging which correlates with pulmonary hypertension and right ventricular dysfunction.     

Extent of myocardial fibrosis and cellular hypertrophy in dilated cardiomyopathy

The distribution of fibrosis and cellular hypertrophy was studied in the hearts of patients with dilated cardiomyopathy (DC). Transmural sections were removed from the left and right ventricular free walls and the ventricular septum of 9 patients with heart failure and 6 control subjects. These sections were stained with hematoxylin-eosin (to determine cell size) and trichrome (to determine percent fibrosis). The sections were separated into equal areas from epicardium to endocardium in the free walls and right to left across the septum. Percent fibrosis was greater in patients with DC (20 +/- 4%) than control subjects (4 +/- 1%, p = 0.0001). A pattern of increasing fibrosis in the left ventricular free wall from epicardium (14 +/- 6%) to endocardium (22 +/- 9%, p less than 0.05) was documented. Fibrosis was greater on the left (21 +/- 12%) than the right (15 +/- 6%, p less than 0.05) side of the septum. No pattern was evident in the right ventricular free wall or in the control group. Myocardial cell diameter was greater in the heart failure group (22 +/- 5 micron) than the control group (17 +/- 2 micron, p less than 0.05), but no pattern of hypertrophy across the walls was seen. The increased fibrosis, the pattern of fibrosis and the increased cell diameter in patients with DC help to characterize DC.