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

Echocardiographic findings of patients with transthyretin amyloid cardiomyopathy

Transthyretin amyloid cardiomyopathy (ATTR-CM) is becoming increasingly recognized with the aging population, advancements in understanding of disease pathobiology and the potential benefits of emerging therapies. Bone scintigraphy, including 99mTc-labeled pyrophosphate scintigraphy, is currently considered the first-line modality for identifying ATTR-CM. Therefore, it is important to increase the preset probability using inexpensive and simple tests including echocardiography. Although there were a lot of typical echocardiographic findings of amyloid cardiomyopathy, unexplained left ventricular (LV) wall thickness, LV apical sparing, and a discrepancy between LV wall thickness and QRS voltage were selected as red flags/clues for ATTR-CM in various current diagnostic algorithms. Although echocardiography is useful for ATTR-CM screening, there are several limitations. Therefore, it is important to perform echocardiography and combine it with physical examination, laboratory findings, and other imaging data.

British Society of Echocardiography guideline for the transthoracic echocardiographic assessment of cardiac amyloidosis

These guidelines form an update of the BSE guideline protocol for the assessment of restrictive cardiomyopathy (Knight et al. in Echo Res Prac, 2013). Since the original recommendations were conceived in 2013, there has been an exponential rise in the diagnosis of cardiac amyloidosis fuelled by increased clinician awareness, improvements in cardiovascular imaging as well as the availability of new and effective disease modifying therapies. The initial diagnosis of cardiac amyloidosis can be challenging and is often not clear-cut on the basis of echocardiography, which for most patients presenting with heart failure symptoms remains the first-line imaging test. The role of a specialist echocardiographer will be to raise the suspicion of cardiac amyloidosis when appropriate, but the formal diagnosis of amyloid sub-type invariably requires further downstream testing. This document seeks to provide a focused review of the literature on echocardiography in cardiac amyloidosis highlighting its important role in the diagnosis, prognosis and screening of at risk individuals, before concluding with a suggested minimum data set, for use as an aide memoire when reporting.

The tricuspid annulus in amyloidosis with cardiac involvement: Detailed analysis from the three-dimensional speckle tracking echocardiographic MAGYAR-Path Study

Introduction

Amyloidosis is a rare condition due to extracellular deposition of excessive amount of protein in parenchymal tissues including the heart. The present study aimed to test whether cardiac amyloidosis (CA) is associated with morphological and functional abnormalities of the tricuspid annulus (TA). For this aim, the results of patients having CA were compared to age- and gender-matched healthy controls by three-dimensional speckle-tracking echocardiography (3DSTE). Moreover, differences in TA parameters between light-chain CA (AL-CA) and transthyretin CA (TTR-CA) were studies as well.

Materials and Methods

The study comprised 27 CA patients (mean age: 62.7 ± 9.1 years, 21 males), their results were compared to those of 20 age- and gender-matched healthy volunteers (59.3 ± 3.8 years, 13 males). Complete two-dimensional Doppler echocardiography and 3DSTE were performed in all CA patients and controls.

Results

Dilated end-diastolic and end-systolic TA diameter, area and perimeter could be detected in all CA patients and in the AL-CA and TTR-CA subgroups, as well. Although only a few TTR-CA patients were involved, morphologic TA parameters proved to be tendentiously higher as compared to those of AL-CA patients. Functional parameters of TA were found to be reduced in CA patients, which were more deteriorated in AL-CA patients.

Conclusions

Dilated TA is associated with its functional deterioration in CA.

Diagnostic Tools for Cardiac Amyloidosis: A Pragmatic Comparison of Pathology, Imaging and Laboratories

Cardiac amyloidosis (CA) is a complex disease considered to be the most common underdiagnosed form of restrictive cardiomyopathy. Accumulation of misfolded proteins called amyloid fibrils in the extracellular space results in clinical deterioration and late diagnosis is associated with morbidity and mortality. Both types of this disease, light chain CA and transthyretin-related CA share many cardiac and extracardiac features that compromise multiple organs such as kidneys, musculoskeletal system, autonomic nervous system, and gastrointestinal tract. Early diagnosis and detection of CA are imperative. Clinicians should maintain a high degree of suspicion among patients with unexplained diastolic heart failure to implement different disease-altering therapies at the early stages of the disease. In this article, we provided a comprehensive review of multiple invasive and non-invasive cardiac imaging modalities with their respective degrees of sensitivities and specificity.

Predictors of cardiac involvement and survival in patients with primary systemic light-chain amyloidosis: roles of the clinical, chemical, and 3-D speckle tracking echocardiography parameters

Background

Light-chain (AL) amyloidosis is the most common type of systemic amyloidosis with poor prognosis. Currently, the predictors of cardiac involvement and prognostic staging systems are primarily based on conventional echocardiography and serological biomarkers. We used three-dimensional speckle tracking echocardiography (STE-3D) measurements of strain, hypothesizing that it could detect cardiac involvement and aid in prediction of mortality.

Methods

We retrospectively analysed 74 consecutive patients with biopsy-proven AL amyloidosis. Among them, 42 showed possible cardiac involvement and 32 without cardiac involvement. LV global longitudinal strain (GLS), global radial strain, global circumferential strain and global area strain (GAS) measurements were obtained.

Results

The GLS and GAS were considered significant predictors of cardiac involvement. The cut-off values discriminating cardiac involvement were 16.10% for GLS, 32.95% for GAS. During the median follow-up of 12.5 months (interquartile range 4–25 months), 20 (27%) patients died. For the Cox proportional model survival analysis, heart rate, cardiac troponin T, NT-proBNP levels, E/e’, GLS, and GAS were univariate predictors of death. Multivariate Cox model showed that GLS ≤ 14.78% and cardiac troponin T ≥ 0.049 mg/l levels were independent predictors of survival.

Conclusions

STE-3D measurements of LV myocardial mechanics could detect cardiac involvement in patients with AL amyloidosis; GLS and cardiac biomarkers can provided prognostic information for mortality prediction.

Diagnostic value of the novel CMR parameter "myocardial transit-time" (MyoTT) for the assessment of microvascular changes in cardiac amyloidosis and hypertrophic cardiomyopathy

BACKGROUND

Coronary microvascular dysfunction (CMD) is present in various non-ischemic cardiomyopathies and in particular in those with left-ventricular hypertrophy. This study evaluated the diagnostic value of the novel cardiovascular magnetic resonance (CMR) parameter "myocardial transit-time" (MyoTT) in distinguishing cardiac amyloidosis from other hypertrophic cardiomyopathies.

METHODS

N = 20 patients with biopsy-proven cardiac amyloidosis (CA), N = 20 patients with known hypertrophic cardiomyopathy (HCM), and N = 20 control patients without relevant cardiac disease underwent dedicated CMR studies on a 1.5-T MR scanner. The CMR protocol comprised cine and late-gadolinium-enhancement (LGE) imaging as well as first-pass perfusion acquisitions at rest for MyoTT measurement. MyoTT was defined as the blood circulation time from the orifice of the coronary arteries to the pooling in the coronary sinus (CS) reflecting the transit-time of gadolinium in the myocardial microvasculature.

RESULTS

MyoTT was significantly prolonged in patients with CA compared to both groups: 14.8 ± 4.1 s in CA vs. 12.2 ± 2.5 s in HCM (p = 0.043) vs. 7.2 ± 2.6 s in controls (p < 0.001). Native T1 and extracellular volume (ECV) were significantly higher in CA compared to HCM and controls (p < 0.001). Both parameters were associated with a higher diagnostic accuracy in predicting the presence of CA compared to MyoTT: area under the curve (AUC) for native T1 = 0.93 (95% confidence interval (CI) = 0.83-1.00; p < 0.001) and AUC for ECV = 0.95 (95% CI = 0.88-1.00; p < 0.001)-compared to the AUC for MyoTT = 0.76 (95% CI = 0.60-0.92; p = 0.008). In contrast, MyoTT performed better than all other CMR parameters in differentiating HCM from controls (AUC for MyoTT = 0.93; 95% CI = 0.81-1.00; p = 0.003 vs. AUC for native T1 = 0.69; 95% CI = 0.44-0.93; p = 0.20 vs. AUC for ECV = 0.85; 95% CI = 0.66-1.00; p = 0.017).

CONCLUSION

The relative severity of CMD (measured by MyoTT) in relationship to extracellular changes (measured by native T1 and/or ECV) is more pronounced in HCM compared to CA-in spite of a higher absolute MyoTT value in CA patients. Hence, MyoTT may improve our understanding of the interplay between extracellular/intracellular and intravasal changes that occur in the myocardium during the disease course of different cardiomyopathies.

Analysis of Cardiac Amyloidosis Progression Using Model-Based Markers

Deposition of amyloid in the heart can lead to cardiac dilation and impair its pumping ability. This ultimately leads to heart failure with worsening symptoms of breathlessness and fatigue due to the progressive loss of elasticity of the myocardium. Biomarkers linked to the clinical deterioration can be crucial in developing effective treatments. However, to date the progression of cardiac amyloidosis is poorly characterized. There is an urgent need to identify key predictors for disease progression and cardiac tissue function. In this proof of concept study, we estimate a group of new markers based on mathematical models of the left ventricle derived from routine clinical magnetic resonance imaging and follow-up scans from the National Amyloidosis Center at the Royal Free in London. Using mechanical modeling and statistical classification, we show that it is possible to predict disease progression. Our predictions agree with clinical assessments in a double-blind test in six out of the seven sample cases studied. Importantly, we find that multiple factors need to be used in the classification, which includes mechanical, geometrical and shape features. No single marker can yield reliable prediction given the complexity of the growth and remodeling process of diseased hearts undergoing high-dimensional shape changes. Our approach is promising in terms of clinical translation but the results presented should be interpreted with caution due to the small sample size.

Role of echocardiography in assessing cardiac amyloidoses: a systematic review

Cardiac amyloidosis is a manifestation of one of several systemic amyloidoses, and is characterized by increased left-ventricular (LV) wall thickness and normal or decreased LV cavity size. Congestive heart failure in cardiac amyloidosis is characterized by a predominant diastolic LV dysfunction, and systolic dysfunction occurs only in late-stage disease. Echocardiography is a noninvasive, reproducible method for assessing cardiac morphology and function in cardiac amyloidosis, and some echocardiographic indices are prognostic for amyloidoses. This review describes the advances in echocardiography and its role in the diagnosis and management of cardiac amyloidoses. Our review suggests that LV longitudinal function and the cyclic variation of myocardial integrated backscatter may be the best predictors of adverse outcomes. In the future, new echocardiographic techniques, such as fully automated echocardiogram interpretation, should provide further useful information for assessing cardiac function and prognosis in cardiac amyloidosis patients.

Recent advances in the noninvasive strategies of cardiac amyloidosis

The heart, like any organ in the body, is susceptible to amyloid deposition. Although more than 30 types of protein can cause amyloidosis, only two types commonly deposit in the ventricular myocardium: amyloid light chain and amyloid transthyretin. Amyloid cardiomyopathy is usually a major determinant of patient outcomes, and the diagnosis of heart involvement can be often relatively under-diagnosed, owing to nonspecific presenting symptoms and signs at a subclinical stage. The diagnosis of cardiac amyloidosis is usually performed by endomyocardial biopsy; however, the invasive nature and related high-risk complications restrict its wide use in clinical settings. Recently, with the advent of innovative techniques used for evaluating cardiac amyloidosis, noninvasive methods become increasingly important, especially in earlier diagnosis, distinguishing typing, risk prediction and response to treatment. Here, we will review recent developments in the noninvasive methods used in the assessment of cardiac amyloidosis, focused on the laboratory biomarkers and imaging modalities.

Imaging of Left Ventricular Hypertrophy: a Practical Utility for Differential Diagnosis and Assessment of Disease Severity

PURPOSE OF REVIEW

Left ventricular hypertrophy (LVH) is often encountered in clinical practice, and it is a risk factor for cardiac mortality and morbidity. Determination of the etiology and disease severity is important for the management of patients with LVH. The aim of this review is to show the remarkable progress in cardiac imaging and its importance in clinical practice.

RECENT FINDINGS

This review focuses on clinical features and characteristic cardiac imaging in LVH caused by various diseases including hypertension, aortic valve stenosis, hypertrophic cardiomyopathy, and secondary cardiomyopathies. The usefulness of echocardiography as a tool of general versatility including hemodynamic evaluation and the usefulness of cardiac magnetic resonance imaging for assessment of cardiac morphology and myocardial tissue characteristics of relevance for LVH are described. Imaging modalities now have central roles in the differentiation and prognostic assessment of LVH.

Left atrial dysfunction in light-chain cardiac amyloidosis and hypertrophic cardiomyopathy - A comparative three-dimensional speckle-tracking echocardiographic analysis from the MAGYAR-Path Study

INTRODUCTION

While cardiac amyloidosis (CA) is a rare systemic disease characterized by extracellular deposition of protein-derived fibrils, hypertrophic cardiomyopathy (HCM) is histopathologically characterized by myocyte hypertrophy and disarray, interstitial fibrosis, and small intramural coronary arteriole dysplasia. The aim of the present study was to compare left atrial (LA) volumetric and functional characteristics between light-chain (AL) CA and HCM by three-dimensional (3D) speckle-tracking echocardiography (STE).

METHODS

The AL-CA group initially consisted of 17 patients with AL-CA, but one patient was excluded due to inadequate image quality, and so the study population consisted of 16 patients (mean age: 64.0±9.6 years, five men). Their results were compared with data on 20 age-matched HCM patients (mean age: 59.8±5.2 years, 10 men) and on 16 age-matched healthy controls (mean age: 58.2±7.2 years, six men). Complete two-dimensional Doppler echocardiography and 3D-STE were performed in all cases.

RESULTS

Significantly increased LA volumes were observed in both AL-CA and HCM compared with the control group. Only active atrial emptying fraction was found to be significantly reduced in AL-CA patients compared to controls. Peak global and mean segmental circumferential, longitudinal and area strains showed significant reductions in AL-CA patients compared with controls, but only peak mean segmental longitudinal strain differed significantly between HCM patients and controls. While no differences were demonstrated in global and mean segmental strain at atrial contraction between HCM patients and controls, AL-CA patients showed reductions in certain strain parameters compared to controls and HCM patients.

CONCLUSIONS

Different patterns of LA functional characteristics were demonstrated in AL-CA and HCM patients by 3D-STE.

Cardiac MR elastography for quantitative assessment of elevated myocardial stiffness in cardiac amyloidosis

Purpose

To evaluate if cardiac magnetic resonance elastography (MRE) can measure increased stiffness in patients with cardiac amyloidosis. Myocardial tissue stiffness plays an important role in cardiac function. A noninvasive quantitative imaging technique capable of measuring myocardial stiffness could aid in disease diagnosis, therapy monitoring, and disease prognostic strategies. We recently developed a high‐frequency cardiac MRE technique capable of making noninvasive stiffness measurements.

Materials and Methods

In all, 16 volunteers and 22 patients with cardiac amyloidosis were enrolled in this study after Institutional Review Board approval and obtaining formal written consent. All subjects were imaged head‐first in the supine position in a 1.5T closed‐bore MR imager. 3D MRE was performed using 5 mm isotropic resolution oblique short‐axis slices and a vibration frequency of 140 Hz to obtain global quantitative in vivo left ventricular stiffness measurements. The median stiffness was compared between the two cohorts. An octahedral shear strain signal‐to‐noise ratio (OSS‐SNR) threshold of 1.17 was used to exclude exams with insufficient motion amplitude.

Results

Five volunteers and six patients had to be excluded from the study because they fell below the 1.17 OSS‐SNR threshold. The myocardial stiffness of cardiac amyloid patients (median: 11.4 kPa, min: 9.2, max: 15.7) was significantly higher (P = 0.0008) than normal controls (median: 8.2 kPa, min: 7.2, max: 11.8).

Conclusion

This study demonstrates the feasibility of 3D high‐frequency cardiac MRE as a contrast‐agent‐free diagnostic imaging technique for cardiac amyloidosis.

Level of Evidence: 2

Technical Efficacy: Stage 2

J. Magn. Reson. Imaging 2017;46:1361–1367.

Use of Noninvasive Imaging in Cardiac Amyloidosis

OPINION STATEMENT

Cardiac involvement in amyloidosis is associated with poor outcomes. The standard test for the diagnosis of cardiac amyloidosis is endomyocardial biopsy but given current advances in noninvasive imaging, the diagnosis is frequently obtained or strongly suspected without biopsy. Echocardiography is the most utilized cardiac imaging modality, particularly myocardial strain measures with this modality have been found to be a predictor of clinical outcomes, superior to traditional parameters. Other known imaging modalities with new, useful protocols for this pathology include nuclear imaging and cardiac magnetic resonance (CMR). In particular, CMR has excellent sensitivity and specificity.

Different patterns of left ventricular rotational mechanics in cardiac amyloidosis-results from the three-dimensional speckle-tracking echocardiographic MAGYAR-Path Study

Cardiac amyloidosis (CA) is an infiltrative disease primarily caused by extracellular tissue deposition of amyloid fibrils in the myocardial interstitium. The aim of the present study was to examine left ventricular (LV) rotational mechanics in biopsy-proven CA by three-dimensional (3D) speckle-tracking echocardiography (STE). Ten patients (65.3±11.5 years, 6 males) with CA entered the study. The mean basal LV rotations were 0.3±3.8°, while mean apical LV rotations proved to be 7.0±3.3°. LV basal and apical rotations were in the same counterclockwise direction in 6 out of 10 CA patients demonstrating near absence of LV twist [LV rigid body rotation (RBR)]. Apico-basal difference was near 3 or less degrees in three patients with LV-RBR, and 6-10 degrees in the other three subjects with LV-RBR. One another patient showed normal rotational mechanics, while two patients had significant hyporotations and one had significant hyperrotations in normal directions. To conclude with, different patterns of LV rotational mechanics could be demonstrated in CA. LV RBR, the near absence of LV twist seems to be a frequent phenomenon in CA.

Infiltrative Cardiomyopathies

Infiltrative cardiomyopathies can result from a wide spectrum of both inherited and acquired conditions with varying systemic manifestations. They portend an adverse prognosis, with only a few exceptions (ie, glycogen storage disease), where early diagnosis can result in potentially curative treatment. The extent of cardiac abnormalities varies based on the degree of infiltration and results in increased ventricular wall thickness, chamber dilatation, and disruption of the conduction system. These changes often lead to the development of heart failure, atrioventricular (AV) block, and ventricular arrhythmia. Because these diseases are relatively rare, a high degree of clinical suspicion is important for diagnosis. Electrocardiography and echocardiography are helpful, but advanced techniques including cardiac magnetic resonance (CMR) and nuclear imaging are increasingly preferred. Treatment is dependent on the etiology and extent of the disease and involves medications, device therapy, and, in some cases, organ transplantation. Cardiac amyloid is the archetype of the infiltrative cardiomyopathies and is discussed in great detail in this review.

Echocardiographic assessment of the cardiac amyloidoses

Cardiac amyloidosis is a cardiomyopathy characterized by increased left ventricular (LV) wall thickness and normal or decreased LV cavity size. Congestive heart failure in cardiac amyloidosis is generally considered a predominantly diastolic phenomenon, with systolic dysfunction only occurring in late-stage disease. Echocardiography is a noninvasive, reproducible method of assessing cardiac features and function in cardiac amyloidosis, and some echocardiographic indices are prognostic for the amyloidoses, with M-mode and 2-dimensional echocardiography able to detect increased LV wall thickness. Moreover, Doppler flow measurements can incrementally assess diastolic LV dysfunction, which is characteristic of cardiac amyloidosis, and provide important prognostic information. Additionally, tissue Doppler imaging can detect subtle changes in both systolic and diastolic LV function, which cannot be detected by Doppler flow measurements, and LV longitudinal strain assessed by color tissue Doppler and speckle tracking echocardiography can provide more accurate LV functional and prognostic information than tissue Doppler imaging. This review describes the advances in echocardiography and its crucial role in the diagnosis and management of cardiac amyloidosis.

Digitalis for treatment of heart failure in patients in sinus rhythm

BACKGROUND

Digitalis glycosides have been in clinical use for the treatment of heart failure (HF) for longer than 200 years. In recent years, several trials have been conducted to address concerns about their efficacy and toxicity.

OBJECTIVES

To examine the effectiveness of digitalis glycosides in treating HF in patients with normal sinus rhythm. To examine the effects of digitalis in patients taking diuretics and angiotensin-converting enzyme inhibitors; in patients with varying severity and duration of disease; in patients with prior exposure to digitalis versus no prior exposure; and in patients with "HF due to systolic dysfunction" versus "HF with preserved ejection fraction."

SEARCH METHODS

Searches on the following databases were updated in May 2013: The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and Dissertation Abstracts. Annual meeting abstracts of the American Heart Association, the American College of Cardiology, and the European Society of Cardiology were searched from 1996 to March 2013. In addition, reference lists provided by the pharmaceutical industry (GlaxoSmithKline and Covis Pharma) were searched.

SELECTION CRITERIA

Included were randomized placebo-controlled trials of 20 or more adult participants of either sex with symptomatic HF who were studied for seven weeks or longer. Excluded were trials in which the prevalence of atrial fibrillation was 2% or greater, or in which any arrhythmia that might compromise cardiac function or any potentially reversible cause of HF such as acute ischemic heart disease or myocarditis was present.

DATA COLLECTION AND ANALYSIS

Articles selected from the searches described above were evaluated in a joint effort of the review authors. The staff of the Cochrane Heart Group ran searches on the Cochrane Central Register of Controlled Trials, MEDLINE, and EMBASE.

MAIN RESULTS

No new studies were identified in the updated searches. Thirteen studies (7896 participants) are included, and major endpoints of mortality, hospitalization, and clinical status, based respectively on 8, 4, and 12 of these selected studies, were recorded and analyzed. The data show no evidence of a difference in mortality between treatment and control groups, whereas digitalis therapy is associated with lower rates of both hospitalization and clinical deterioration. The largest study, in which most participants were taking angiotensin-converting enzyme inhibitors, showed a significant rise in "other cardiac" deaths, possibly due to arrhythmias. However collectively, these findings were based on studies done before beta-blockers, as well as angiotensin receptor blockers and aldosterone antagonists, became widely used to treat HF.

AUTHORS' CONCLUSIONS

The literature indicates that digitalis may have a useful role in the treatment of patients with HF who are in normal sinus rhythm. New trials are needed to elucidate the importance of the dosage of digitalis and its usefulness in the era of beta-blockers and other agents shown to be effective in treating HF.

Matrix elasticity regulates the optimal cardiac myocyte shape for contractility

Concentric hypertrophy is characterized by ventricular wall thickening, fibrosis, and decreased myocyte length-to-width aspect ratio. Ventricular thickening is considered compensatory because it reduces wall stress, but the functional consequences of cell shape remodeling in this pathological setting are unknown. We hypothesized that decreases in myocyte aspect ratio allow myocytes to maximize contractility when the extracellular matrix becomes stiffer due to conditions such as fibrosis. To test this, we engineered neonatal rat ventricular myocytes into rectangles mimicking the 2-D profiles of healthy and hypertrophied myocytes on hydrogels with moderate (13 kPa) and high (90 kPa) elastic moduli. Actin alignment was unaffected by matrix elasticity, but sarcomere content was typically higher on stiff gels. Microtubule polymerization was higher on stiff gels, implying increased intracellular elastic modulus. On moderate gels, myocytes with moderate aspect ratios (∼7:1) generated the most peak systolic work compared with other cell shapes. However, on stiffer gels, low aspect ratios (∼2:1) generated the most peak systolic work. To compare the relative contributions of intracellular vs. extracellular elasticity to contractility, we developed an analytical model and used our experimental data to fit unknown parameters. Our model predicted that matrix elasticity dominates over intracellular elasticity, suggesting that the extracellular matrix may potentially be a more effective therapeutic target than microtubules. Our data and model suggest that myocytes with lower aspect ratios have a functional advantage when the elasticity of the extracellular matrix decreases due to conditions such as fibrosis, highlighting the role of the extracellular matrix in cardiac disease.

Differentiating cardiac amyloidosis and hypertrophic cardiomyopathy by use of three-dimensional speckle tracking echocardiography

INTRODUCTION

Cardiac amyloidosis (CA) and hypertrophic cardiomyopathy (HCM) are important differential diagnosis of left ventricular hypertrophy. The aim of this study was to investigate if three-dimensional (3D) speckle tracking-derived functional parameters enabled differentiation of CA and HCM by a disease-specific pattern.

METHODS

Twelve patients with CA and 12 patients with HCM were included. CA and HCM were diagnosed by contrast-enhanced cardiovascular magnetic resonance (CMR). Three-dimensional speckle tracking echocardiography with wall motion analysis was performed for strain (radial [RS(%)], longitudinal [LS (-%)], and circumferential [CS (-%)]), rotation (ROT [degree]), and twist (TWT [degree]). Intergroup comparison included normalized values from 49 healthy volunteers.

RESULTS

Averaged RS, LS, CS, ROT, and TWT were investigated at basal, midventricular, and apical levels. With some exceptions, 3D speckle tracking function parameters were mostly lower in the HCM and minimal in the CA group as compared to controls. Comparing CA and HCM, basal RS was significantly reduced in patients with amyloidosis (7.5 ± 19.7 vs. 22.3 ± 22.7; P < 0.0001), furthermore the "physiological" gradient of basoapically decreasing RS, which was reduced, but still preserved in HCM, showed a clear "inverse pattern" in patients with amyloidosis, comprising a gradual increase from base to apex. Correlation analysis of 3D speckle tracking function and CMR late gadolinium enhancement (LGE) revealed high inverse correlation of RS and LGE in CA (r =-0.82) and only mild correlation in HCM, followed by CS as second best parameter. An increasing/decreasing basoapical RS gradient yielded a sensitivity of 83% versus the CMR-derived diagnosis "CA" and "HCM."

CONCLUSIONS

Three-dimensional speckle tracking echocardiography demonstrated significant differences in CA and HCM. The basoapical RS gradient displayed oppositional characteristics in CA and HCM, suggesting a "function-pattern-based" differentiation of amyloidosis and HCM.

Echocardiographic evaluation of systolic and diastolic function in patients with cardiac amyloidosis

The typical appearance of cardiac amyloidosis using standard echocardiographic techniques is usually a late finding only in patients with relatively advanced stages of the disease. Early noninvasive identification of cardiac amyloidosis is of growing clinical importance. Newer echocardiographic techniques, including tissue Doppler imaging and deformation imaging (strain rate imaging and 2-dimensional speckle tracking), are powerful tools for quantifying regional myocardial motion and deformation. Using these advanced techniques, early functional impairment in cardiac amyloidosis may be detectable when the results of standard echocardiography are still normal or inconclusive. This review provides a comprehensive overview of the different echocardiographic approaches for the assessment of systolic and diastolic function in patients with cardiac amyloidosis. Special attention is paid to regional myocardial function assessed by tissue Doppler imaging, strain rate imaging, and 2-dimensional speckle-tracking imaging.

Hemodynamic and angiocardiographic observations in familial amyloidosis with polyneuropahy

Eleven patients with familial amyloidosis with polyneuropathy were studied by heart catheterization; eight of them also by right and left ventriculography and selective coronary angiography. Signs of congestive heart failure, often reported as typical of cardiac amyloidosis, were found in only one patient. The systolic function was relatively unimpaired, but in several patients hemodynamic data suggested restrictive cardiomyopathy. Six patients showed signs of right or left ventricular outflow tract obstruction. Thus, no uniform hemodynamic pattern could be identified, but the changes found indicate impaired diastolic function.

Cardiac amyloidosis mimicking hypertrophic cardiomyopathy

Amyloid infiltration of the heart may frequently masquerade as other cardiac disorders. The extended use of echocardiography may contribute to an erroneous diagnosis of hypertrophic cardiomyopathy, as both conditions show several features in common. This was the case with the patient reported below. A low QRS amplitude, an increased right ventricular wall thickness, thickened cardiac valves, and a pericardial effusion may, however, indicate amyloid infiltration. The diagnosis of systemic amyloidosis of immunocytic origin was subsequently established in our patient. A definitive diagnosis of amyloid heart disease requires endomyocardial biopsy, but it is suggested that typical noninvasive findings together with demonstration of amyloid in an organ other than the heart is sufficient for a reliable diagnosis. In addition, systemic manifestations may contribute to a correct diagnosis in generalized amyloidosis. Our patient had features consistent with the rare muscle pseudohypertrophy syndrome, which is associated with immunocytic amyloidosis.

Differentiation of hypertrophic cardiomyopathy and cardiac amyloidosis from other causes of ventricular wall thickening by two-dimensional strain imaging echocardiography

Hypertension is the most common cause of left ventricular (LV) hypertrophy. However, multiple causes can lead to LV hypertrophy, each of which has different histological and mechanical properties. To assess the value of a novel speckle-tracking echocardiographic measurement of myocardial strain and strain rate in defining the mechanical properties of LV hypertrophy, 20 patients with asymmetric hypertrophic cardiomyopathy, 24 patients with secondary LV hypertrophy, 12 patients with biopsy-proved confirmed cardiac amyloidosis, and 22 age-matched healthy asymptomatic volunteers were studied. Patients with amyloidosis had severe diastolic dysfunction, and myocardial deformation was significantly decreased. The new technique allowed cardiac amyloid to be easily differentiated from the other categories. In patients with hypertrophic cardiomyopathy, there was segmental myocardium dysfunction as assessed by strain imaging. LV global systolic velocity and radial displacement were higher, and abnormal relaxation was more frequent, in the group with secondary LV hypertrophy than in normal controls. In conclusion, the observations from strain parameters derived from speckle tracking were consistent with the known underlying pathology of each condition, which speaks to the value of strain imaging. Cardiac amyloid profoundly alters all strain parameters, and analysis of these parameters could aid in the diagnosis.

Current therapeutic strategies in cardiac amyloidosis

Amyloidosis is a systemic disease in which clinical manifestations are caused by the replacement of normal tissue with insoluble amyloid fibrils. Cardiac involvement causes a restrictive cardiomyopathy and is associated with poor functional outcomes. Cardiac magnetic resonance imaging and measurement of B-type natriuretic peptide are particularly helpful in distinguishing restrictive cardiomyopathy from constrictive pericarditis, but a tissue biopsy is required to make the diagnosis of amyloidosis. Although standard treatment options for congestive heart failure may provide symptomatic relief in cardiac amyloidosis, prognosis remains dismal. Judicious diuretic use remains the mainstay of therapy, but achieving optimal fluid balance is difficult because patients are usually "preload dependent." Angiotensin-converting enzyme inhibitors in low doses are often helpful but may lead to orthostatic hypotension, particularly in patients who also have involvement of the autonomic nervous system. beta Blockers may be useful if given relatively early in the disease process, but should be used with caution in patients with advanced disease because they may exacerbate symptoms. Therapy aimed at the underlying disease process in primary systemic amyloidosis is based on treatment regimens used in multiple myeloma, such as melphalan and prednisone. These offer limited benefit when cardiac involvement is significant, but newer treatments, including the novel anthracycline 4'-iodo-4'-deoxydoxorubicin, potentially combined with autologous stem cell transplantation, offer some hope for the future.

Cardiac and Vascular Hypertrophy in Fabry Disease

Objectives— Fabry disease is an X-linked disorder resulting from α-galactosidase A deficiency. The cardiovascular findings include left ventricular hypertrophy (LVH) and increased intima-media thickness of the common carotid artery (CCA IMT). The current study examined the possible correlation between these parameters. To corroborate these clinical findings in vitro, plasma from Fabry patients was tested for possible proliferative effect on rat vascular smooth muscle cells (vascular smooth muscle cell [VSMC]) and mouse neonatal cardiomyocytes.

Methods and Results— Thirty male and 38 female patients were enrolled. LVH was found in 60% of men and 39% of women. Increased CCA IMT was equally present in males and females. There was a strong positive correlation between LV mass and CCA IMT (r 2 =0.27; P <0.0001). VSMC and neonatal cardiomyocyte proliferative response in vitro correlated with CCA IMT (r 2 =0.39; P <0.0004) and LV mass index (r 2 =0.19; P =0.028), respectively.

Conclusions— LVH and CCA IMT occur concomitantly in Fabry suggesting common pathogenesis. The underlying cause may be a circulating growth-promoting factor whose presence has been confirmed in vitro.

Digitalis for treatment of congestive heart failure in patients in sinus rhythm: a systematic review and meta-analysis

BACKGROUND

This review summarizes the current status of randomized trials of digitalis in treating patients with congestive heart failure who are in sinus rhythm. Methods and results Randomized double-blind placebo-controlled trials of 20 or more adult patients followed for 7 weeks or more were selected. We identified 13 trials that met the inclusion criteria, comprising a total of 7896 patients. Of this number, 7755 patients contributed to information on mortality, 7262 to information on hospitalization for worsening heart failure, and 1096 to information on clinical status. Patients treated with digitalis compared with placebo had an odds ratio and confidence intervals for mortality of 0.98 (0.89, 1.09), for hospitalization of 0.68 (0.61, 0.75), and for a lesser degree of deterioration in clinical status of 0.31 (0.21, 0.43).

CONCLUSIONS

The literature indicates that the drug has no effect on long-term mortality, but reduces the incidence of hospitalization, and has a positive effect on the clinical status of symptomatic patients. The drug has beneficial effects in patients who remain symptomatic despite being appropriately treated with diuretics and angiotensin-converting enzyme inhibitors. However the effects of coadministration with beta-blockers, spironolactone, and valsartan remain uncertain.

Left atrial systolic function in primary and familial amyloidosis: assessment from left atrial volume change

The severity of left ventricular involvement may differ between primary (PA) and familial amyloidosis (FA). This study examined whether differences in left atrial (LA) systolic function are also present. Twenty-eight patients (18 men, 10 women, aged 59 +/- 12 years) with PA, 17 (11 men, 6 women, aged 40 +/- 11 years) with FA, and 25 normal controls (18 men, 7 women, aged 56 +/- 14 years) underwent transthoracic M-mode, two-dimensional, and Doppler echocardiography. Left atrial volumes were determined at mitral valve (MV) opening (maximal, Vmax), electrocardiographic P wave (onset of atrial systole, Vp), and MV closure (minimal, Vmin) from the apical two-and four-chamber views using the biplane area-length method. Left atrial systolic function was assessed with the LA active emptying volume (ACTEV) = Vp-Vmin and fraction (ACTEF) = ACTEV/Vp. The E/A ratio was increased (1.34 +/- 0.93 vs. 0.89 +/- 0.3), whereas deceleration time was decreased (168.1 +/- 33.7 vs. 196.2 +/- 34.2 ms) in PA compared with FA (p<0.05). Vmax and Vp were similar in PA and FA and greater than in the controls (46.6 +/- 14 vs. 40 +/- 11.4 vs. 27.1 +/- 6.3 cm3/m2, p<0.01, and 33.4 +/- 11.6 vs. 29.7 +/- 10.8 vs. 16.8 +/- 3.8 cm3/m2, p<0.01, respectively). The ACTEV was lower in PA and in the controls than in FA (6.7 +/- 2 vs. 6.2 +/- 2.2 vs. 8.5 +/- 3.3, respectively, p<0.05). The ACTEF was lower in PA than in FA and both were lower than those in the controls (20 +/- 5% vs. 28 +/- 7% vs. 36 +/- 11%, respectively, p<0.01). Despite a similar increase in LA volume, LA systolic dysfunction is more pronounced in PA than in FA. This is most likely due to the restrictive left ventricular physiology possibly associated with depressed LA contractility in the former.

Tissue Doppler imaging in the evaluation of patients with cardiac amyloidosis

PURPOSE OF REVIEW

Although two-dimensional, M-mode, and Doppler echocardiography have played a major role in the assessment of amyloid deposition in the heart, diagnosis of cardiac amyloidosis (CA) based on these conventional techniques is often only possible once the disease is in a relatively advanced stage. To optimize survival, early diagnosis and institution of therapy are essential. Recently, tissue Doppler imaging (TDI) and myocardial strain rate (SR) have emerged as important clinical tools in the assessment of CA.

RECENT FINDINGS

Tissue Doppler imaging-derived modalities including TDI velocities, strain, and SR are currently being used in the early diagnosis and evaluation of patients with CA. Although these new indices have been examined in relatively few patients, findings suggest an important and expanding role of TDI in amyloid infiltration of the heart.

SUMMARY

This review summarizes the recent literature addressing the role of TDI velocities, strain, and SR in the diagnosis and assessment of CA.

Differentiation of constrictive pericarditis from restrictive cardiomyopathy using mitral annular velocity by tissue Doppler echocardiography

This study evaluated the diagnostic role of early diastolic mitral annular velocity (E') by tissue Doppler echocardiography for differentiating constrictive pericarditis from restrictive cardiomyopathy (primary restrictive cardiomyopathy and cardiac amyloidosis). The study group consisted of 75 patients (53 men, 22 women; mean age 62 years, range 27 to 87). Of these, 23 patients had surgically confirmed constrictive pericarditis, 38 had biopsy-proved systemic amyloidosis and typical echocardiographic features of cardiac involvement, and 14 had primary restrictive cardiomyopathy. Standard mitral inflow characteristics were measured. Tissue Doppler echocardiography was used to measure E' at the septal annulus. E' was significantly higher in patients with constrictive pericarditis than in those with primary restrictive cardiomyopathy or cardiac amyloidosis (12.3 vs 5.1 cm/second, p <0.001). An E' cut-off value > or =8 cm/second resulted in 95% sensitivity and 96% specificity for the diagnosis of constrictive pericarditis. There was no overlap of E' between patients who had constrictive pericarditis and those who had cardiac amyloidosis. In a subgroup analysis of restrictive cardiomyopathy, E' of patients who had cardiac amyloidosis was significantly lower than that of patients who had primary restrictive cardiomyopathy (4.6 vs 6.3 cm/second, p <0.001). Thus, E' velocity can distinguish between constrictive pericarditis and restrictive cardiomyopathy with a specific cut-off value in patients with clinical and echocardiographic evidence of diastolic heart failure.

Evaluation of right ventricular dysfunction in patients with cardiac amyloidosis using tei index

BACKGROUND

Cardiac amyloidosis is an infiltrative disease causing predominant diastolic dysfunction and systolic dysfunction at its advanced stage. Right ventricular (RV) dysfunction is an independent predictor of poor prognosis in congestive heart failure and cardiomyopathies. However, the assessment of RV function is still technically difficult because of the complicated geometry of the RV. The recently proposed Tei index, obtained from the cardiac time interval analysis, allows noninvasive and quantitative estimation of global ventricular function without geometric evaluation. Therefore, this study was designed to assess RV function for patients with cardiac amyloidosis.

METHODS

Study patients consisted of 30 consecutive patients with biopsy specimen-proven cardiac amyloidosis and 50 control subjects. Patients were classified as having early or advanced stage of cardiac amyloidosis on the basis of mean left ventricular wall thickness < 15 mm or >/= 15 mm. Tei index, defined as the sum of isovolumetric contraction and relaxation time divided by ejection time, was obtained from tricuspid and pulmonary Doppler flow velocity.

RESULTS

RV Tei index was significantly increased for patients with cardiac amyloidosis (0.54 +/- 0.16 vs 0.28 +/- 0.05, amyloidosis vs control, P <.001). The incidences of abnormal RV isovolumetric contraction time, ejection time, isovolumetric relaxation time, and Tei index in all patients with cardiac amyloidosis were 63%, 43%, 73%, and 83%, respectively. The same incidences were 50%, 13%, 63%, and 75% in the early stage and 68%, 54%, 77%, and 86% in the advanced stage, respectively.

CONCLUSION

Patients with cardiac amyloidosis frequently have RV dysfunction even in its early stage. Tei index allows simple, noninvasive, and nongeometric estimation of RV dysfunction in patients with cardiac amyloidosis.

Digitalis for treatment of congestive heart failure in patients in sinus rhythm

BACKGROUND

Digitalis glycosides have been in clinical use in the treatment of congestive heart failure (CHF) for more than 200 years. In recent years several trials have been conducted to address concerns about efficacy and toxicity. Although a systematic review of the literature was published in 1990, an update is required to include more current trials.

OBJECTIVES

To examine the effectiveness of digitalis glycosides in treating CHF in patients with normal sinus rhythm. To examine the effect of digitalis in patients taking diuretics, angiotensin converting enzyme inhibitors, and beta-blockers; patients with varying severity and duration of disease; patients with prior exposure to digitalis vs. no prior exposure; and patients with "CHF due to systolic dysfunction" vs. "CHF with preserved systolic function."

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (CENTRAL) 2003 Issue 4, MEDLINE (1966 to December 2003) and EMBASE (1990 to December 2003) were searched. Dissertation Abstracts and annual meeting abstracts of the American Heart Association, American College of Cardiology, and European Society of Cardiology were also searched from 1996-2003. In addition, reference lists provided by the pharmaceutical industry (Glaxo Wellcome Inc.) were searched.

SELECTION CRITERIA

Included were randomized placebo-controlled trials of 20 or more adult patients of either sex with symptomatic CHF who were studied for seven weeks or more. Excluded were trials in which the prevalence of atrial fibrillation was 2% or greater, or in which any arrhythmia that might compromise cardiac function or any potentially reversible cause of CHF such as acute ischemic heart disease or myocarditis was present.

DATA COLLECTION AND ANALYSIS

Articles selected from the searches described above were evaluated as a joint effort of the coauthors. The staff of the Cochrane Heart Group ran searches on the Cochrane Central Register of Controlled Trials.

MAIN RESULTS

Thirteen articles meeting the defined criteria were identified, and major endpoints of mortality, hospitalization, and clinical status, based respectively upon 8, 4, and 12 of these selected studies, were recorded and analyzed. The data show that there is no evidence of a difference in mortality between treatment and control groups, whereas digitalis therapy is associated with a lower rate of hospitalization and of clinical deterioration.

REVIEWERS' CONCLUSIONS

The literature indicates that digitalis has a useful role in the treatment of patients with CHF who are in normal sinus rhythm.

Digitalis for treatment of congestive heart failure in patients in sinus rhythm

BACKGROUND

Digitalis glycosides have been in clinical use in the treatment of congestive heart failure for more than 200 years. In recent years several trials have been conducted to address concerns about efficacy and toxicity. Although a systematic review of the literature was recently published, an update is required to include more current trials.

OBJECTIVES

To examine the effectiveness of digitalis glycosides in treating congestive heart failure in patients with normal sinus rhythm. To examine the effect of digitalis in patients taking diuretics, ACE inhibitors, and beta blockers; patients with varying severity and duration of disease; patients with prior exposure to digitalis vs. no prior exposure; and patients with diastolic vs. systolic dysfunction.

SEARCH STRATEGY

Electronic databases were searched between 1966 and 2000. Dissertation Abstracts and annual meeting abstracts of the American Heart Association, American College of Cardiology, and European Society of Cardiology were searched from 1996-2000. In addition, reference lists provided by the pharmaceutical industry (Glaxo Wellcome Inc.) were searched.

SELECTION CRITERIA

Included were randomized placebo-controlled trials of 20 or more adult patients of either sex with symptomatic congestive heart failure who were studied for seven weeks or more. Excluded were trials in which the prevalence of atrial fibrillation was 2% or greater, or in which any arrhythmia that might compromise cardiac function or any potentially reversible cause of heart failure such as acute ischemic heart disease or myocarditis was present.

DATA COLLECTION AND ANALYSIS

Articles selected from the searches described above were reviewed by one of the coauthors, and validated by staff from the central office of the Heart Collaborative Review Group in Bristol, UK.

MAIN RESULTS

Eleven articles meeting the defined criteria were identified, and major endpoints of mortality, hospitalization, and clinical status, based respectively upon on 8, 4, and 10 of these selected studies, were recorded and analyzed. The data show that there is no difference in mortality between treatment and control groups, whereas digitalis therapy is associated with a lower rate of hospitalization and of clinical deterioration.

REVIEWER'S CONCLUSIONS

The literature indicates that digitalis has a useful role in the treatment of patients with congestive heart failure who are in normal sinus rhythm.

Amyloidosis

Amyloidosis is considered rare but has an incidence similar to that of Hodgkin's disease and chronic granulocytic leukemia. The diagnosis should be considered in any patient with unexplained nephrotic-range proteinuria, heart failure, peripheral neuropathy, or hepatomegaly. If a monoclonal protein is found in a patient with any of these clinical presentations, a biopsy should be performed and the specimen stained with Congo red. The simplest source of diagnostic material is subcutaneous fat tissue. Treatment usually consists of chemotherapy, which may be oral and low dose or high dose with stem cell rescue.

Features and prognosis of exertional syncope in light-chain associated AL cardiac amyloidosis

Syncope is common in AL amyloid heart disease and in almost 1/3 of our patients who experienced syncope, it was precipitated by physiologic stress. Stress-precipitated syncope was associated with a poor prognosis in such patients, both in terms of their median survival of 2 months and was frequently a precursor of sudden cardiac death.

[Cardiac pathology of extracardiac origin (II). The cardiac repercussion of amyloidosis and hemochromatosis]

Although rare, amyloidosis and hemochromatosis are the infiltrative diseases in which the heart is more frequently involved. The most common clinical presentation is heart failure with hemodynamic features of restrictive heart disease in cardiac amyloidosis. The diagnosis is often made because of symptoms of other organ involvement, although sometimes cardiac symptoms may be the initial manifestation. The non-specific clinical presentation and the low prevalence of these cardiomyopathies make the diagnosis difficult if the clinician does not suspect it. Once symptoms develop, the evolution is fast. Usually, the unsatisfactory and ineffective treatment of amyloidosis and hemochromatosis contribute to the poor prognosis. The indication of cardiac transplantation in advanced cases is questionable because of the high recurrence of the illness.

Right ventricular dilation in primary amyloidosis: an independent predictor of survival

This study was designed to characterize the geometry and function of the right ventricle and its prognostic significance in patients with primary (AL) cardiac amyloidosis. AL amyloidosis is an infiltrative systemic disease that can result in thickening of heart structures and rapidly progressive congestive heart failure due to restrictive ventricular physiology and eventual systolic dysfunction. Thirty-seven patients with AL amyloid heart involvement and 20 normal control subjects were evaluated using 2-dimensional and Doppler echocardiography. Based on the ratio of left-to-right end-diastolic ventricular chamber areas, patients were classified into 2 groups: 25 patients with disproportionate right ventricular (RV) dilation (left ventricular to RV ratio < or = 2) and 12 with a ventricular area ratio > 2. Patients with a relatively dilated right ventricle (ratio < or = 2) had a shorter median survival (4 months) compared with patients with an area ratio > 2 (10 months, p <0.003). Of multiple clinical, echocardiographic, and Doppler features entered into a multifactorial model, a ventricular area ratio < or = 2 remained the only independent predictor of survival. Patients with AL amyloid heart disease represent a heterogeneous population with regard to both prognosis and the relative degree of right to left ventricular dilation. RV dilation in patients with amyloid heart disease appears to be associated with more severe involvement and is associated with a very poor prognosis with a median survival of only 4 months.

Primary amyloidosis and syncope

A 59-year-old caucasian consulted our clinic with symptoms of dizziness and exertional syncope. The combination of myocardial hypertrophy diagnosed by echocardiography, together with a history of peripheral neuropathy made us suspect cardiac amyloidosis which was later proven by endomyocardial biopsy. A graded exercise test and two Holter monitoring studies revealed neither rhythm nor conduction abnormalities. A head-up tilt test revealed a vasovagal vasodepressor response.