The functional defect in amyloid heart disease. The "stiff heart" syndrome

Doppler index combining systolic and diastolic myocardial performance: clinical value in cardiac amyloidosis

OBJECTIVES

This study was designed to determine the clinical value of a Doppler-derived index of combined systolic and diastolic myocardial performance in the assessment of cardiac amyloidosis.

BACKGROUND

Cardiac amyloidosis is an infiltrative disease with diastolic and systolic dysfunction. Therefore, the index of myocardial performance combining systolic and diastolic time intervals could be a useful predictor of clinical outcome in cardiac amyloidosis.

METHODS

The study included 45 patients with biopsy-proved amyloidosis and 45 age-matched normal subjects. All patients had typical echocardiographic features of amyloid cardiac involvement. A Doppler-derived index, defined as the sum of isovolumetric contraction time and isovolumetric relaxation time divided by ejection time, was measured from left ventricular outflow and mitral inflow Doppler velocity profiles recorded during routine echocardiography. The index as well as conventional systolic or diastolic echocardiographic/Doppler variables were related to subsequent outcome.

RESULTS

The isovolumetric contraction and relaxation times were prolonged and ejection time was shortened (p < 0.001) in patients with amyloidosis compared with that in normal subjects, resulting in a marked increase of the index from normal values (p < 0.001). In the amyloid group the index was highest in patients with a low stroke index or with both shortened mitral deceleration time and lower ejection fraction. By univariate analysis, New York Heart Association functional class, the index, ejection fraction and mitral deceleration time were significant predictors of outcome. However, by multivariate stepwise regression analysis, functional class and the index were the only independent predictors of survival.

CONCLUSIONS

The Doppler-derived index of combined systolic and diastolic myocardial performance correlates with global cardiac dysfunction and is a useful predictor of clinical outcome in patients with cardiac amyloidosis.

Value of dynamic respiratory changes in left and right ventricular pressures for the diagnosis of constrictive pericarditis

BACKGROUND

Conventional cardiac catheterization criteria for the diagnosis of constrictive pericarditis (CP) rely on equalization of intracardiac pressures and have many recognized limitations. Recently, Doppler echocardiographic methods have been used to examine dynamic respiratory changes of increased ventricular interdependence and dissociation of intrathoracic and intracardiac pressures for the diagnosis of CP. These pathophysiological features may be best delineated by cardiac catheterization. Therefore, we studied the accuracy of these dynamic respiratory changes in left ventricular and right ventricular pressure for the diagnosis of CP at cardiac catheterization.

METHODS AND RESULTS

High-fidelity manometric catheters and respirometry were used to study 36 patients: 15 patients with surgically proven CP (group 1) and 21 patients with other causes of heart failure (group 2). Conventional cardiac catheterization variables used to establish the diagnosis of CP lacked sensitivity and specificity and failed to distinguish between these groups. However, the finding of discordance between right ventricular and left ventricular pressures during inspiration, a sign of increased ventricular interdependence, accurately distinguished patients in group 1 from those in group 2 (P < .05).

CONCLUSIONS

Examination of dynamic respiratory changes indicating increased ventricular interdependence may be helpful in the diagnosis of CP in the cardiac catheterization laboratory.

Cardiac amyloidosis: a review and report of a new transthyretin (prealbumin) variant

Cardiac amyloidosis is caused by amyloid deposits derived from different human plasma proteins. It can lead to cardiac conduction disturbances, restrictive cardiomyopathy, and low output heart failure. The heart is variably involved during the development of systemic amyloidosis and seems to be more frequently affected in immunoglobulin (primary) than in reactive (secondary) amyloidosis. Amyloid is common in the elderly. Isolated atrial amyloid, for which a major subunit is the atrial natriuretic peptide, seems to be three times more frequent than senile cardiac amyloid, which is derived from normal prealbumin (transthyretin). Like polyneuropathy, cardiac amyloidosis is a prominent clinical feature of hereditary amyloidosis, namely of the autosomal dominant transthyretin (TTR) type. All 28 cases of TTR amyloidoses reported so far were heterozygotes for a single nucleotide change in the gene for TTR that resulted in amino acid substitutions in the mature protein. A new TTR genetic variant is reported in a German family where the index patient presented at the age of 63 with anginal pain and arrhythmia. Electrocardiography was suggestive of a pseudoinfarction pattern, and echocardiography and cardiac catheterisation showed signs of hypertrophic nonobstructive cardiomyopathy with increased ventricular filling pressures and a prominent "a" wave. Amyloid of the TTR type was identified by immunohistochemistry in the endomyocardial biopsy specimen. Hybrid isoelectric focusing established heterozygosity by showing normal TTR protein and an electrically neutral TTR variant differing from all known TTR variants so far. The patient died in an accident before investigations were complete. Electrophoretic analysis of the plasma from his first degree relatives (son, daughter, brother, and mother) identified the asymptomatic 22 year old son as an apparently heterozygous carrier of the mutant TTR protein. Comparative tryptic peptide mapping and sequencing showed that isoleucine at position 68 of the amino acid sequence was replaced by leucine.

A fatal case of constrictive pericarditis due to a marked, selective pericardial accumulation of amyloid

Distinguishing constrictive pericarditis from restrictive cardiomyopathy, usually due to amyloidosis, is a relatively frequent and difficult diagnostic problem. This report describes, for the first time, a patient with constrictive pericarditis caused by direct, extensive infiltration of the pericardium by amyloid, with only minimal amyloid in the myocardium, and a normal heart weight of 320 g. This patient demonstrates that amyloid may be predominantly deposited in the pericardium and actually cause constrictive pericarditis, as well as simulate its hemodynamic presentation by myocardial deposition. Given a clinical and hemodynamic presentation compatible with either constrictive or restrictive disease, an endomyocardial biopsy or other biopsy revealing amyloidosis does not necessarily rule out pericardial constriction that may be due to amyloid infiltration. The relationship between constrictive pericarditis, seen in this patient, and the other more common manifestations of amyloid heart disease, and the hemodynamic profiles of amyloid cardiomyopathy and constrictive pericarditis are reviewed.

Assignment of patients into the classification of cardiomyopathies

The original classifications of the cardiomyopathies based on anatomic criteria from radiographic and necropsy studies, as well as hemodynamic criteria from clinical and catheterization data, have been supplemented in recent years by information from noninvasive techniques. Echocardiography, radionuclide methods, and ambulatory ECG, in particular, have facilitated the ethical screening of family members and those less symptomatic than patients on whom the original classification was based. These powerful methods show a broad spectrum of anatomy and ventricular physiology along the natural history of and within the traditional categories of the cardiomyopathies. They also provide data on the effect of ventricular loading conditions affecting a range of diastolic filling patterns. This review has attempted to point out the areas of overlap among and/or controversy about the categories that have led us to a feeling of frustration when trying to neatly classify individual patients. The addition of filling patterns from Doppler echocardiography and nuclear angiography to the standard methods has been reviewed and hopefully will lend more perspective to the range of physiology seen in these conditions. The categories of cardiomyopathy should not be seen as excluding patients with the newly recognized variations in anatomy and ventricular filling patterns. Rather, the classification provides a framework on which to build and expand our understanding of these important conditions.

Amyloid heart disease manifested by systemic arterial thromboemboli

Amyloid heart disease characteristically produces a stiff heart syndrome whereby diastolic filling is impaired yet systolic function is well preserved. We report two patients with this pattern of amyloid heart disease, both of whom developed cardiogenic thromboemboli. The rarity of this complication is striking given the pathophysiologic bases of amyloid heart disease. Investigation of contributing causes revealed that the phenomena appeared to represent the cumulative effects of disorders producing stasis, endothelial disturbance, and probable abnormalities in blood coagulability, the classic Virchow's triad revisited. Understanding of the pathophysiologic basis of this event leads to specific suggestions for workup and management in this patient population.

Cardiac evaluation

Over the past decade there has been a dramatic, rapid development of new imaging modalities used in the evaluation of the cardiac patient. These newer techniques are frequently complex and specialized in their application and interpretation. Nonetheless, the prevalence of cardiac disease in the United States, and the wide application of these diagnostic tests, mandate that the well-rounded clinician has a basic understanding of the utility of these diagnostic modalities. Unfortunately, the burgeoning field of cardiac imaging seems at times to overshadow our most important basic diagnostic tools, namely, the history, physical exam, chest radiograph, and electrocardiogram (ECG). This review will attempt to impart a basic understanding of the newer cardiac diagnostic tests and their utility in various disease states. Emphasis on the importance of the basic clinical exam and the precise integration of specific diagnostic tests into the cardiac evaluation will be emphasized. The article will deliver a basic review of exercise treadmill testing, echocardiography, radionuclide imaging techniques, magnetic resonance imaging, and cardiac catheterization. It is hoped that this review will impart to the noncardiologist clinician a basic understanding of the cardiovascular diagnostic techniques so that an accurate, precise, cost-effective, efficient diagnostic plan for the patient with cardiovascular disease can be developed and applied.

Constrictive pericarditis versus restrictive cardiomyopathy: a reappraisal and update of diagnostic criteria

Distinguishing constrictive pericarditis from restrictive cardiomyopathy is a difficult clinical challenge. We review published reports in which hemodynamic criteria were used to differentiate these two diagnoses. There were 82 cases of constriction and 37 cases of restriction. The overall predictive accuracy of the difference between right and left ventricular end-diastolic pressures (RVEDP and LVEDP), RV systolic pressure, and the ratio of RVEDP to RV systolic pressure were 85%, 70%, and 76%, respectively. If all three criteria were concordant, the probability of having correctly classified the patient was greater than 90%. However, one fourth of patients could not be classified by hemodynamic criteria. There are few data to support the use of hemodynamic measurements after exercise or volume infusion to separate these two groups. Numerous recent studies have reported on the ability of left ventriculography, Doppler echocardiography, or radionuclide angiography to distinguish constriction from restriction. Many of the proposed indices appear promising, but these studies suffer from small sample size, potential selection bias, and complexity of the proposed criteria, which have limited their widespread application. New imaging technologies, such as CT scanning or MRI have been applied in a limited number of cases, but appear to be a sensitive means of detecting abnormal pericardium. Endomyocardial biopsy has proven useful in establishing the diagnosis of infiltrative cardiomyopathies, eliminating in those cases the need for surgical intervention. The finding of myocarditis must be considered a nonspecific finding that does not preclude thoracotomy. Since constrictive pericarditis is a surgically curable condition, the distinction between constrictive and restrictive disease is of critical importance. Taking into account the relative contribution of data derived from hemodynamic, imaging,and biopsy studies, we propose an algorithm for the selection of appropriate candidates for pericardial biopsy and stripping.

A case of cardiac amyloidosis presenting with symptoms of exertional syncope

A 54-year-old man presented with symptoms of exertional syncope. Cardiac amyloidosis was diagnosed by endomyocardial biopsy. Exercise tolerance test revealed a failure of increased heart rate followed by sinus arrest, associated with syncope. Autopsy revealed amyloid deposits in the sinoatrial node.

Doppler assessment of diastolic function in cardiac amyloidosis

The hallmark of cardiac amyloidosis is abnormal diastolic function secondary to amyloid infiltration of the ventricular walls, which accounts for the term "stiff heart syndrome." The abnormal diastolic function has not yet been well characterized, however. Thus, we assessed left and right ventricular diastolic function in 53 patients with cardiac amyloidosis. We measured the left and right ventricular inflow and venous flow velocities with Doppler echocardiography and found a range of Doppler filling abnormalities. These abnormalities were dependent on the degree of amyloid infiltration of the heart as measured by mean left ventricular wall thickness. Patients with advanced cardiac amyloidosis (a wall thickness greater than or equal to 15 mm) showed restriction, while patients with early cardiac amyloidosis (a wall thickness less than 15 mm) showed abnormal relaxation or normal filling. In another study, during a 13-month follow-up, patients with early cardiac amyloidosis showed Doppler patterns that evolved from abnormal relaxation through a normal stage, to an advanced stage of restrictive disease. We also have demonstrated the importance of left ventricular inflow variables in predicting the outcome of patients with cardiac amyloidosis. We concluded that Doppler echocardiography is useful in characterizing abnormal diastolic function in patients with cardiac amyloidosis.

Fatty infiltration: another restrictive cardiomyopathic pattern

Restrictive cardiomyopathies have been shown to occur as result of infiltrative processes from a variety of sources. The current report describes an obese male, who was found to have hemodynamic evidence of a restrictive cardiac process. His pericardium was proven to be normal and an incisional biopsy obtained of the myocardium during coronary artery bypass surgery demonstrated histologic evidence of fatty infiltration of myocardium. Review of the restrictive and pathology literature is discussed and indicates that this is the first report to demonstrate the association between fatty infiltration and hemodynamic findings consistent with a restrictive cardiomyopathy.

Prognostic significance of Doppler measures of diastolic function in cardiac amyloidosis. A Doppler echocardiography study

BACKGROUND

We have previously characterized the left ventricular diastolic filling abnormalities in cardiac amyloidosis by Doppler methods. The various filling patterns were shown to be related to the degree of cardiac amyloid infiltration. The purpose of this study was to determine the value of Doppler diastolic filling variables for assessing prognosis in cardiac amyloidosis.

METHODS AND RESULTS

We performed pulsed-wave Doppler studies of the left ventricular inflow and obtained clinical follow-up data in 63 consecutive patients with biopsy-proven systemic amyloidosis. All patients had typical echocardiographic features of cardiac involvement. The patients were subdivided into two groups according to deceleration time: Group 1 (33 patients) had a deceleration time of 150 msec or less, indicative of restrictive physiology, and group 2 (30 patients) had a deceleration time of more than 150 msec. Of the 63 patients, 32 (51%) died during a mean follow-up period of 18 +/- 12 months. Of these deaths, 25 (78%) were cardiac deaths, and 19 of the 25 patients (76%) were from group 1. The 1-year probability of survival in group 1 was significantly less than that in group 2 (49% versus 92%, p less than 0.001). Bivariate analysis revealed that the combination of the Doppler variables of shortened deceleration time and increased early diastolic filling velocity to atrial filling velocity ratio were stronger predictors of cardiac death than were the two-dimensional echocardiographic variables of mean left ventricular wall thickness and fractional shortening.

CONCLUSIONS

Doppler-derived left ventricular diastolic filling variables are important predictors of survival in cardiac amyloidosis.

Is technetium-99 m-pyrophosphate scintigraphy valuable in the diagnosis of cardiac amyloidosis?

Amyloidosis is a systemic disease frequently involving the myocardium and leading to functional disturbances of the heart. Amyloidosis can mimic other cardiac diseases. A conclusive clinical diagnosis of cardiac involvement can only be made by a combination of different diagnostic methods. In 7 patients with myocardial amyloidosis we used a combined first-pass and static scintigraphy with technetium-99 m-pyrophosphate. There was only insignificant myocardial uptake of the tracer. The first-pass studies however revealed reduced systolic function in 4/7 patients and impaired diastolic function in 6/7 patients. Therefore, although cardiac amyloid could not be demonstrated in the static scintigraphy due to amyloid fibril amount and composition, myocardial functional abnormalities were seen in the first-pass study.

Serial Doppler echocardiographic follow-up of left ventricular diastolic function in cardiac amyloidosis

A spectrum of left ventricular diastolic filling abnormalities noted on Doppler echocardiography has been demonstrated in patients with cardiac amyloidosis. To determine how these filling abnormalities evolve over time and the significance of any change, serial pulsed wave Doppler studies of left ventricular inflow were performed over 12.6 +/- 4.9 months in 41 consecutive patients (36 men and 15 women, mean age 59 +/- 11 years) with typical two-dimensional echocardiographic features of cardiac involvement. The measurements were peak left ventricular inflow in early diastole (E) and atrial contraction (A) velocities, E/A ratio, deceleration time and isovolumetric relaxation time. Patients were classified by mean left ventricular wall thickness into an early group (less than 15 mm) of 24 patients and an advanced group (greater than or equal to 15 mm) of 17 patients. The total group showed an increased E/A ratio (1.7 +/- 0.9 versus 1.4 +/- 0.9, p = 0.009) and decreased deceleration time (164 +/- 57 versus 174 +/- 51 ms, p = 0.11) at follow-up compared with baseline study. The early group showed significant changes in the E/A ratio (1.6 +/- 1.0 versus 1.2 +/- 0.7, p = 0.001) between the two studies. Seven patients (29%) in the early group showed a change from an abnormal relaxation or "normal" pattern to one of restriction, coincident with increased symptoms in six of these patients. Fifteen (88%) of the 17 patients in the advanced group did not show significant changes in the measures during the follow-up study, but these patients already showed a restrictive pattern.(ABSTRACT TRUNCATED AT 250 WORDS)

Impairment of left ventricular diastolic function during coronary artery bypass grafting

Twelve patients were studied by transoesophageal Doppler echocardiography to determine diastolic function during coronary artery bypass grafting. Haemodynamic and Doppler-derived variables were measured after induction of anaesthesia and after closure of the sternum. Early diastolic filling of the left ventricle decreased from 55% to 35% during surgery. The contribution of atrial contraction to left ventricular filling increased from 41% to 62% (p less than 0.001). We conclude that coronary artery bypass grafting results in impairment of diastolic function during the operation.

Comprehensive Doppler assessment of right ventricular diastolic function in cardiac amyloidosis

To assess right ventricular diastolic function in cardiac amyloidosis, pulsed wave Doppler ultrasound measurements of right ventricular inflow velocities and superior vena cava and hepatic vein flow velocities with respiratory monitoring were performed in 41 patients with primary systemic amyloidosis and two-dimensional echocardiographic features of cardiac involvement. Right ventricular diastolic function was abnormal in 31 (76%) of these patients, the major abnormality being a short deceleration time (less than 150 ms) in 21 (68%), suggesting restriction. In contrast, 7 (23%) of the 31 patients had a decreased ratio of early (E) and late (A) diastolic peak flow velocities and a prolonged deceleration time (greater than 240 ms), suggesting abnormal relaxation. The patients were classified into two groups on the basis of right ventricular free wall thickness: group 1, less than 7 mm and group 2, greater than or equal to 7 mm. Compared with normal values, group 1 showed an increased peak late flow velocity (44 +/- 19 versus 39 +/- 6 cm/s; p less than 0.01) and a decreased E/A velocity ratio (1.1 +/- 0.4 versus 1.5 +/- 0.3; p less than 0.01). Group 2 showed a markedly shortened deceleration time (151 +/- 37 versus 225 +/- 28 ms; p less than 0.01), characteristic of restriction. In the overall group, superior vena cava peak flow velocity was decreased in systole and increased in diastole and flow reversals during inspiration were increased compared with normal values. Hepatic venous flow velocities were similar to those in the superior vena cava except for larger flow reversals in the hepatic vein. Thus, in cardiac amyloidosis, right ventricular diastolic function is abnormal. There is a spectrum of right ventricular filling abnormalities and the restrictive filling pattern is seen only in the advanced stages of the disease.

Doppler characterization of left ventricular diastolic function in cardiac amyloidosis

Sixty-four patients with primary systemic amyloidosis-53 with two-dimensional echocardiographic features of cardiac involvement (Group I) and 11 without cardiac involvement (Group II)--underwent Doppler echocardiographic assessment of left ventricular diastolic function. Pulsed wave Doppler recordings of left ventricular inflow velocities and pulmonary vein flow velocities with respiratory monitoring in these patients were compared with findings in a normal group. Patients in Group I showed striking abnormalities of left ventricular diastolic filling when classified into subgroups by mean left ventricular wall thickness: early greater than 12 but less than 15 mm; advanced greater than or equal to 15 mm. In early amyloidosis, relaxation was abnormal, with decreased peak early velocity (75 +/- 20 versus 86 +/- 16 cm/s; p less than 0.01), increased late velocity (71 +/- 22 versus 56 +/- 13 cm/s; p less than 0.01), decreased early to late velocity ratio (1.2 +/- 0.6 versus 1.6 +/- 0.5; p less than 0.01) and prolonged isovolumic relaxation time (87 +/- 15 versus 73 +/- 13 ms; p less than 0.01) compared with normal values. In advanced amyloidosis, there was a restrictive filling pattern with a markedly shortened deceleration time (148 +/- 50 versus 199 +/- 32 ms; p less than 0.001), decreased pulmonary vein peak systolic flow velocity (34 +/- 16 versus 54 +/- 12 cm/s; p less than 0.01) and increased diastolic flow velocity (55 +/- 20 versus 44 +/- 12 cm/s; p less than 0.01) compared with normal values. Group and the subgroup with early amyloidosis had similar flow velocity patterns. Thus, this study documents that in cardiac amyloidosis, a spectrum of diastolic filling abnormalities exists; the restrictive filling pattern is seen only in the advanced stages.

Impaired left ventricular diastolic filling in patients with familial amyloid polyneuropathy: a pulsed Doppler echocardiographic study

To assess left ventricular diastolic filling in patients with amyloid heart disease 12 patients with familial amyloid polyneuropathy and 15 normal subjects were studied by pulsed Doppler echocardiography. None of the patients had clinical evidence of overt heart disease or restrictive cardiomyopathy and only two of them showed ventricular wall thickening. The peak flow velocity of rapid diastolic filling and the acceleration rate of early diastolic inflow were significantly lower in patients with familial amyloid polyneuropathy than in controls. The pressure half time was significantly longer in patients than in controls. In addition, the peak flow velocity during atrial contraction and the ratio of atrial peak flow velocity to rapid diastolic peak flow velocity were significantly greater in patients than in controls. Although there were no significant correlations between measurements of diastolic filling and clinical findings in patients with familial amyloid polyneuropathy, the ratio of atrial peak flow velocity to rapid diastolic peak flow velocity was significantly related to left ventricular posterior wall thickness. These findings suggest that in patients with cardiac amyloidosis without restrictive cardiomyopathy, abnormal left ventricular diastolic filling, manifested by a reduction in the rate and volume of rapid diastolic filling with enhanced atrial contraction, can be seen even in the early stage of the disease.

Radionuclide angiographic assessment of left ventricular diastolic filling in amyloid heart disease: a study of patients with familial amyloid polyneuropathy

To assess left ventricular diastolic filling in amyloid heart disease, 17 patients with familial amyloid polyneuropathy and 20 normal subjects were examined by radionuclide angiography. None of the patients showed clinical evidence of restrictive cardiomyopathy. All but two patients had normal left ventricular ejection fraction. Peak filling rate was significantly lower and time to peak filling rate was significantly greater in patients than in normal subjects (2.60 +/- 0.52 versus 3.10 +/- 0.44 EDV/s, p less than 0.001, and 215 +/- 53 versus 147 +/- 18 ms, p less than 0.001, respectively). The mean left ventricular filling volume during rapid diastolic filling and atrial systole in patients was 54.5 +/- 19.5% and 44.2 +/- 21.6% of the stroke volume, respectively, compared with 83.8 +/- 6.6% (p less than 0.001) and 20.0 +/- 6.0% (p less than 0.001), respectively, in normal subjects. Although 10 of the 14 patients without clinical evidence of overt heart disease had normal ventricular wall thickness as well as normal ejection fraction, 8 of the 10 showed abnormal diastolic filling. In patients with familial amyloid polyneuropathy, indexes of diastolic filling were significantly related to ventricular wall thickness alone. The incidence and magnitude of abnormalities in time to peak filling rate and contribution of rapid filling as well as atrial systole to ventricular filling increased with age and duration of illness. Thus, abnormal diastolic filling can be seen even in the early stage of familial amyloid polyneuropathy and may be related to myocardial amyloid deposition as well as to fibrosis. Careful consideration should be given to age and duration of illness when diastolic filling is assessed in this disorder.

Restrictive cardiomyopathy and constrictive pericarditis: non-invasive distinction by digitised M mode echocardiography

It is difficult to distinguish between restrictive cardiomyopathy and constrictive pericarditis on the basis of clinical findings and simple investigation. Cardiac catheterisation has been the reference standard for diagnosis but even this does not always permit an accurate distinction. A Summagraphics digitiser and Prime 750 computer system were used to digitise the echocardiograms of 15 patients with restrictive cardiomyopathy, 10 with constrictive pericarditis and a group of 20 age and sex matched normal subjects of similar age and sex distribution. Compared with controls, patients with restrictive cardiomyopathy showed a significant reduction in the following variables (a) decreased fractional shortening, (b) decreased peak left ventricular filling and emptying rates, (c) decreased percentage posterior wall thickening, and (d) decreased peak left ventricular posterior wall thickening and thinning rates. Whereas patients with constrictive pericarditis only had significantly reduced peak left ventricular filling and posterior wall thinning rates and significantly increased posterior wall thinning rate. When patients with restrictive cardiomyopathy were compared with those with constrictive pericarditis the significant differences were: (a) decreased peak left ventricular emptying rate, (b) decreased percentage posterior wall thickening, and (c) decreased peak left ventricular posterior wall thickening and thinning rates. Digitisation of M mode echocardiograms, with particular attention to posterior wall function, may be a useful adjunct to cardiac catheterisation in distinguishing restrictive cardiomyopathy from constrictive pericarditis.

Evaluation of right and left ventricular function in hard metal workers

Ingested cobalt has previously been associated with the development of a congestive cardiomyopathy. Despite occasional reports of cardiomyopathy after industrial exposure to cobalt, this association remains controversial. In a study of 30 cemented tungsten carbide workers with a mean duration of exposure to cobalt of 9.9 +/- 5.3 years radionuclide ventriculography was performed to study right and left ventricular ejection fractions at rest and exercise. For the entire group, rest and exercise biventricular function was normal. There was, however, a weak but significant inverse correlation between duration of exposure and resting left ventricular function (r = -0.40, p less than 0.03). Workers with abnormal chest x ray findings (9/30) had relatively lower exercise right ventricular ejection fractions (45% +/- 6 v 52% +/- 7, p less than 0.02). An inverse relation was also found between rest and exercise right ventricular ejection fraction and severity of parenchymal abnormalities on x ray examination (r = -0.44, p less than 0.01 and r = -0.41, p less than 0.02). Diminished right ventricular reserve was probably due to fibrotic lung disease and early cor pulmonale. Although overt left ventricular dysfunction was not present, prolonged exposure to industrial cobalt may be a weak cardiomyopathic agent with unknown long term significance.

Two-dimensional and Doppler echocardiographic assessment of infiltrative cardiomyopathy

Infiltrative cardiomyopathies can be divided by disease into infiltrative and storage disorders that show an increase in ventricular wall thickness caused by infiltration of pathologic substances between cells, as with amyloid and sarcoid, or deposition within cells, as with iron, glycogen, and lipid. Two-dimensional and Doppler echocardiography are powerful noninvasive tools in the assessment of the anatomic and functional characteristics of these disorders. With cardiac amyloidosis as the prototype, the constellation of findings of a small or normal left ventricular cavity size; markedly increased thickness of the ventricular walls, associated with a highly abnormal texture; and biatrial enlargement make up its characteristic appearance. However, there is a wide spectrum of abnormalities in this disorder, depending on the stage and duration of heart involvement. Doppler assessment of diastolic function is frequently abnormal in cardiac amyloidosis. Cardiac sarcoidosis usually is evident by a dilated segmental cardiomyopathy with regional wall abnormalities. Similarly, hemochromatosis appears as a dilated cardiomyopathy with normal wall thickness. The echocardiographic appearance of glycogen and glycolipid storage diseases is similar to cardiac amyloidosis, and biochemical analysis may be necessary for differentiation. Thus echocardiography is an important tool in the characterization of infiltrative cardiomyopathies.

Senile cardiac amyloidosis with myocardial dysfunction. Diagnosis by endomyocardial biopsy and immunohistochemistry

Senile cardiac amyloid discovered at autopsy is usually regarded as an incidental finding. However, in immunohistochemical studies of autopsy material, three distinct forms of senile cardiovascular amyloid have been characterized, including a systemic form that diffusely infiltrates the cardiac ventricles. The systemic form can be identified immunohistochemically with use of antiserum to human prealbumin. We diagnosed senile systemic amyloidosis causing cardiac dysfunction in five men (57 to 72 years old) by using antiserum to prealbumin in myocardial biopsy tissue. Clinically, the five patients were indistinguishable from patients with nonsecretory immunoglobulin-derived primary amyloidosis with cardiac involvement; only immunohistochemical staining of myocardial tissue distinguished between the two entities. This distinction is important, because the treatment and prognosis of the two disorders are different. We recommend immunohistochemical staining of myocardial tissue for prealbumin in patients with biopsy-proved cardiac amyloid in whom no monoclonal immunoglobulin light chain is detectable in the serum or urine.

Cardiac stimulation threshold in familial amyloidosis with polyneuropathy

It has been suggested that a higher cardiac stimulation threshold reduces the applicability of pacemaker therapy in cardiac amyloidosis. We therefore reviewed threshold data in patients with familial amyloidosis with polyneuropathy (FAP), which is an inherited type of systemic amyloidosis, invariably involving the heart. Fourteen FAP patients treated with a pacemaker were studied. The mean (+/- SD) voltage stimulation threshold during implantation was 1.0 +/- 0.5 V, and noninvasive follow-up 6 months later revealed a mean Vario threshold of 1.9 +/- 0.5 V. Beyond this time, the threshold tended to be stable, and high threshold exit block did not occur in any patient. Several FAP patients did show a moderately elevated threshold, and a multiprogrammable pulse generator with a high output capability is recommended when pacemaker therapy is considered in these patients.

Doppler echocardiographic analysis of left ventricular filling in treated hypertensive patients

Early detection and prevention of cardiac dysfunction is an important goal in the management of hypertensive patients. In this study, Doppler echocardiography was used to evaluate the pattern of left ventricular diastolic filling in 38 subjects: 18 treated hypertensive patients (blood pressure 141 +/- 17/83 +/- 10 mm Hg, mean +/- SD) without other coronary risk factors and 20 risk-free normotensive subjects of similar age (47 +/- 10 and 49 +/- 13 years, respectively). Peak velocity of late left ventricular filling due to the atrial contraction was greater in hypertensive compared with normotensive subjects (69 +/- 14 versus 52 +/- 13 cm/s; p less than 0.001). Peak velocity of late filling was significantly greater in hypertensive versus normotensive subjects in those aged 50 years or younger and those older than age 50 (65 +/- 12 versus 50 +/- 11; p less than 0.01 and 75 +/- 15 versus 56 +/- 15 cm/s; p less than 0.05, respectively). In hypertensive subjects, peak velocity of late filling did not correlate with routine indexes of hypertensive heart disease (including posterior wall thickness and left ventricular mass), systolic and diastolic blood pressure or duration of hypertension. These results indicate that increased velocity of late left ventricular filling may be independent of left ventricular hypertrophy and persist despite effective blood pressure control.

Yield of endomyocardial biopsy in patients with biventricular failure. Comparison of patients with normal vs reduced left ventricular ejection fraction

Twenty five patients with biventricular failure underwent endomyocardial biopsy procedures. Twelve of these 25 patients had normal left ventricular ejection fraction. Endomyocardial biopsy sampling was useful in eight of 12 patients (67 percent) with biventricular failure and normal left ventricular ejection fraction. Biopsy specimens in five of these 12 patients demonstrated endocardial or infiltrative heart disease and excluded these diseases in three other patients with constrictive pericarditis. This study suggests that the clinical presentation of biventricular failure, combined with the noninvasive determination of a normal left ventricular ejection fraction, is helpful in selecting patients for endomyocardial biopsy study. Patients with biventricular failure and normal left ventricular ejection fractions have a high probability of having pericardial or infiltrative heart disease, conditions that often can be differentiated only by analysis of myocardial tissue. Hemodynamic assessment of patients without infiltrative processes further allows one to eliminate those patients with a high likelihood of having constrictive pericardial disease.

Unsuspected amyloidosis and cardiac arrest following mitral valve replacement

We performed an autopsy on a 58-year-old female with previously unsuspected cardiac amyloidosis. One day prior to expiration the patient underwent a mitral valve replacement with a Bjork-Shiley prosthesis for mitral valve regurgitation. The valvular defect along with the massive myocardial amyloidosis which created a restrictive cardiomyopathy, were the etiology of the patient's poor cardiac output and subsequent demise.

Cardiac amyloidosis: combined use of two-dimensional echocardiography and electrocardiography in noninvasive screening before biopsy

Cardiac amyloidosis (CA) presenting with intractable congestive heart failure, electrocardiographic (ECG) normal or low voltage, and conduction or rhythm disturbances, is rapidly fatal. During life, CA often mimics other cardiomyopathies so that definitive diagnosis depends on demonstration of amyloid on myocardial biopsy. On two-dimensional echocardiography (2-D echo), nonspecific features, such as increased ventricular wall thicknesses, predominant diastolic dysfunction, and diffuse myocardial "sparkling," are consistently found in CA. The combined presence of these 2-D echo features and normal or low voltage on ECG is highly suggestive of CA, allows differentiation from other cardiomyopathies, and might be useful in noninvasive screening before myocardial biopsy.

Ventricularization of right atrial wave form in amyloid restrictive cardiomyopathy

Two patients with biopsy-proven amyloid restrictive cardiomyopathy were presented. Both cases showed ventricularization of an elevated right atrial pressure wave form in absence of tricuspid regurgitation. Possible explanations for this finding as well as its clinical implications are discussed. This observation indicates that ventricularization of right atrial pressure wave form could be a useful hemodynamic sign in amyloid restrictive cardiomyopathy in absence of tricuspid regurgitation. Furthermore, such a finding does not seem to be specific for tricuspid regurgitation.

Endomyocardial biopsy: a review of the literature

A review of the literature relating to endomyocardial biopsy (EMB) is presented. This is considered important at this time since EMB is being utilized with increasing frequency, particularly for the diagnosis of myocarditis. The development of the technique is briefly outlined. Emphasis is placed on the clinical application of EMB in the various primary cardiomyopathies (dilated, hypertrophic, restrictive, and obliterative), the infiltrative secondary cardiomyopathies (amyloidosis, sarcoidosis, hemochromatosis), myocarditis, as well as such conditions as adriamycin cardiotoxicity, cardiac transplant rejection, and Kawasaki disease. More controversial application of EMB in primary mitral valve prolapse (Barlow's syndrome), idiopathic ventricular arrhythmias, and the elucidation of the enigmatic finding of angina with angiographically normal coronary arteries is detailed. Experience with immunological and biochemical investigation of biopsy material, as well as with virus isolation and drug assays in the myocardium, is alluded to. Complications encountered with this procedure are also discussed, and its future role is contemplated.

Clinical significance of histopathologic patterns of cardiac amyloidosis

Cardiac amyloidosis may be asymptomatic or an important cause of progressive heart failure and refractory arrhythmia. To identify the morphologic markers of clinically significant cardiac amyloidosis, we analyzed the hearts of 47 patients with autopsy-proven cardiac amyloidosis (21 with primary amyloidosis [AL] and 26 with senile cardiac amyloidosis [SCA]) histologically for the extent and pattern of amyloid deposits. The extent of amyloid deposition was graded 1 through 4, corresponding with less than 10%, 10 to 25%, 26 to 50%, and more than 50% histologic involvement of the myocardium, respectively. The pattern of deposits was classified as nodular, perifiber, or mixed type, and the presence or absence of vascular involvement was determined. The hearts with primary amyloidosis showed predominantly high-grade deposits (76% grades 3 and 4), a perifiber (65%) or mixed (30%) pattern of deposits, and frequent (90%) vascular involvement. The hearts with senile cardiac amyloidosis tended to have low-grade deposits (62% grades 1 and 2), a nodular pattern (92%) of deposits, and infrequent (4%) vascular involvement. Clinically significant cardiac amyloidosis was associated with grade 2 or greater amyloid deposits in the heart and with involvement of intramyocardial arterioles.

The cardiomyopathies: a review of terminology, pathology and pathogenesis

A classification of the cardiomyopathies based on functional and morphological features is outlined, a detailed account of the pathology of each type is presented and possible pathogenetic mechanisms are reviewed. Myocarditis and its relationship to cardiomyopathy is considered and the main morphological and aetiological factors are presented.

Cardiomyopathy: how far have we come in 25 years, how far yet to go?

Twenty-five years ago clinical investigators began to appreciate that cardiomyopathy is an important and reasonably common form of heart disease. Since then, several functional classifications have been proposed, the specific myocardial diseases have been classified and chronic ischemic ventricular failure has been described. The boundary separating myocarditis from dilated cardiomyopathy remains hazy and, despite intensive research, the causes of dilated cardiomyopathy remain obscure. In particular, we still do not understand the role that may be played by viral infection and alcohol. Myocardial biopsy has proved useful in patients with specific myocardial disorders, heart transplant recipients and patients receiving Adriamycin, but is disappointing in patients with dilated cardiomyopathy. It has become increasingly evident that exercise capacity does not correlate with ventricular function, being highly dependent on peripheral factors. Measurements of oxygen consumption during exercise promise to be useful in assessing treatment of dilated cardiomyopathy. True restrictive cardiomyopathy is uncommon, and the term should be reserved for cardiomyopathies that meet strict criteria. A restrictive component to filling is common to many cardiac disorders, including some cases of cardiac amyloidosis. The concept of hypertrophic cardiomyopathy has evolved rapidly over the past 25 years, and continues to evolve. The importance of arrhythmia as a cause of sudden death is becoming increasingly clear. The place of calcium channel blocking agents in the treatment of hypertrophic cardiomyopathy will probably emerge soon. Amiodarone is finding an increasing role in the treatment of dilated and hypertrophic cardiomyopathy. Surgical treatment is still required for some patients despite unanswered questions on how it works.

Manifestation and ultrastructural typing of amyloid deposits in the heart

Using light and electron microscopy, 65 cases of amyloid deposits in the heart were examined. Five different groups were distinguished: I. isolated atrial amyloidosis, II. senile cardiac amyloidosis, III. cardiac amyloid accompanying chronic infections and tumors, IV. cardiac amyloid accompanying plasma cell dyscrasia, V. idiopathic cardiac amyloidosis. Seen structurally, no principal differences in the precise localization of the amyloid deposits were found in any of the groups investigated. Amyloid is always deposited in the vicinity of cells with myocytic cell differentiation (i.e. the heart muscle cells, non-striated muscle cells of the vessels), whereby the relevant basement membranes serve as conductors. A systematic relationship between amyloid and the collagenous fibers of the interstitium or the tunica adventitia of the vessels could not be demonstrated, which shows the concept "pericollagen" to be inadequate for the morphological characterization of amyloid deposits in the heart. Whereas for group I a localized mechanism for the production of amyloid must be considered, in the case of groups II-V a vascular principle expression of a generalized amyloidosis seems to be the major factor. The question of the differing concentration of amyloid deposits in the heart suggests that localized factors (e.g. changes in the myocytic basement membranes) and quantitative changes of the amyloid-building proteins may also be important.