Martha Grogan

Left ventricular dysfunction due to atrial fibrillation in patients initially believed to have idiopathic dilated cardiomyopathy.

Ten patients aged 22 to 80 years (median 57) with severe left ventricular (LV) dysfunction and atrial fibrillation (AF) with rapid ventricular response were evaluated after therapy. Because most patients were unaware of their arrhythmia, duration was usually unknown. All patients had heart failure symptoms; 9 presented with New York Heart Association class III or IV disability, and 1 with class II disability. Initial LV ejection fraction ranged from 12 to 30% (median 25). No patient had symptomatic coronary artery disease (4 underwent angiography). Myocarditis and infiltrative processes were excluded by biopsy in 5 patients. All patients were considered initially to have idiopathic dilated cardiomyopathy with secondary AF. Ventricular rate was controlled in all patients, with sinus rhythm restored in 5. At follow-up (median 30 months, range 3 to 56), all patients were asymptomatic. LV ejection fraction after treatment ranged from 40 to 64% (median 52). It is concluded that in some patients initially considered to have idiopathic dilated cardiomyopathy, AF with rapid ventricular response may be the primary cause rather than the consequence of severe LV dysfunction. LV dysfunction may be completely reversible with ventricular rate control.

Role of cardiac magnetic resonance imaging in the detection of cardiac amyloidosis.

OBJECTIVES Our aim was to evaluate the role and mechanism of late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) in identifying cardiac amyloidosis (CA) and to investigate associations between LGE and clinical, morphologic, functional, and biochemical features. BACKGROUND CA can be challenging to diagnose by echocardiography. Recent studies have demonstrated an emerging role for LGE-CMR. METHODS LGE-CMR was performed in 120 patients with amyloidosis. Cardiac histology was available in 35 patients. The remaining 85 patients were divided into those with and without echocardiographic evidence of CA. RESULTS Of the 35 patients with histologically verified CA, abnormal LGE was present in 34 (97%) patients and increased echocardiographic left ventricular wall thickness in 32 (91%) patients. Global transmural or subendocardial LGE (83%) was most common and was associated with greater interstitial amyloid deposition (p = 0.03). Suboptimal myocardial nulling (8%) and patchy focal LGE (6%) were also observed. LGE distribution matched the deposition pattern of interstitial amyloid. Among patients without cardiac histology, LGE was present in 86% of those with evidence of CA by echocardiography and in 47% of those without evidence of CA by echocardiography. In patients without echocardiographic evidence of CA, the presence of LGE was associated with worse clinical, electrocardiographic (ECG), and cardiac biomarker profiles. In all patients, LGE presence and pattern was associated with New York Heart Association functional class, ECG voltage, left ventricular mass index, right ventricular wall thickness, troponin-T, and B-type natriuretic peptide levels. CONCLUSIONS LGE is common in CA and detects interstitial expansion from amyloid deposition. Global transmural or subendocardial LGE is most common, but suboptimal myocardial nulling and focal patchy LGE are also observed. LGE-CMR may detect early cardiac abnormalities in patients with amyloidosis with normal left ventricular thickness. The presence and pattern of LGE is strongly associated with clinical, morphologic, functional, and biochemical markers of prognosis.

Nonbiopsy Diagnosis of Cardiac Transthyretin Amyloidosis

Background— Cardiac transthyretin (ATTR) amyloidosis is a progressive and fatal cardiomyopathy for which several promising therapies are in development. The diagnosis is frequently delayed or missed because of the limited specificity of echocardiography and the traditional requirement for histological confirmation. It has long been recognized that technetium-labeled bone scintigraphy tracers can localize to myocardial amyloid deposits, and use of this imaging modality for the diagnosis of cardiac ATTR amyloidosis has lately been revisited. We conducted a multicenter study to ascertain the diagnostic value of bone scintigraphy in this disease. Methods and Results— Results of bone scintigraphy and biochemical investigations were analyzed from 1217 patients with suspected cardiac amyloidosis referred for evaluation in specialist centers. Of 857 patients with histologically proven amyloid (374 with endomyocardial biopsies) and 360 patients subsequently confirmed to have nonamyloid cardiomyopathies, myocardial radiotracer uptake on bone scintigraphy was >99% sensitive and 86% specific for cardiac ATTR amyloid, with false positives almost exclusively from uptake in patients with cardiac AL amyloidosis. Importantly, the combined findings of grade 2 or 3 myocardial radiotracer uptake on bone scintigraphy and the absence of a monoclonal protein in serum or urine had a specificity and positive predictive value for cardiac ATTR amyloidosis of 100% (positive predictive value confidence interval, 98.0–100). Conclusions— Bone scintigraphy enables the diagnosis of cardiac ATTR amyloidosis to be made reliably without the need for histology in patients who do not have a monoclonal gammopathy. We propose noninvasive diagnostic criteria for cardiac ATTR amyloidosis that are applicable to the majority of patients with this disease.

Long-term outcome of patients with biopsy-proved myocarditis: Comparison with idiopathic dilated cardiomyopathy

OBJECTIVES The study objectives were 1) to assess the long-term outcome of patients with biopsy-proved lymphocytic myocarditis (Dallas criteria), and 2) to compare the outcome of these patients with that of patients with idiopathic dilated cardiomyopathy. BACKGROUND Endomyocardial biopsy is frequently performed in patients presenting with dilated cardiomyopathy to identify lymphocytic myocarditis. Most previous studies of the natural history of myocarditis were performed before the establishment of the Dallas criteria. Thus, it is important to evaluate the prognostic value of positive endomyocardial biopsy findings in patients presenting with dilated cardiomyopathy, using standardized criteria for lymphocytic myocarditis. METHODS All endomyocardial biopsy results from the Mayo Clinic (October 1979 to April 1988) with a diagnosis of myocarditis were reclassified according to the Dallas criteria. Patients whose biopsy specimens showed borderline or lymphocytic myocarditis were included in the study group; those with systemic inflammatory diseases known to be associated with myocardial involvement were excluded. Study group survival was compared with that for a cohort of patients with idiopathic dilated cardiomyopathy seen at the Mayo Clinic from 1976 to 1987 who had endomyocardial biopsy findings negative for myocarditis. RESULTS Biopsy specimens from 41 patients met the Dallas criteria for a diagnosis of myocarditis (n = 28) or borderline myocarditis (n = 13). Of these 41 patients, 9 were excluded because of the presence of systemic diseases known to be associated with myocarditis, and 5 patients were excluded because of lack of available follow-up data. The myocarditis study group therefore included 27 patients (10 with borderline myocarditis, 17 with myocarditis). Fifty-eight patients with a diagnosis of idiopathic dilated cardiomyopathy who underwent endomyocardial biopsy served as the comparison cohort. Ejection fraction was lower in patients with idiopathic dilated cardiomyopathy ([mean +/- SD] 25 +/- 11%) than in those with myocarditis (38 +/- 19%, p = 0.001), even though a higher proportion of myocarditis group patients were in New York Heart Association functional class III or IV (63%) than patients in the dilated cardiomyopathy group (30%, p = 0.005). There was no difference in 5-year survival rate between the myocarditis and idiopathic dilated cardiomyopathy groups (56% vs. 54%, respectively). CONCLUSIONS This study demonstrates that the long-term outcome of patients with biopsy-proved myocarditis seen in a referral setting is poor, although no different from that of patients with idiopathic dilated cardiomyopathy. With the current lack of proved effective treatment for lymphocytic myocarditis and no demonstration of survival benefit for patients with myocarditis, these data suggest that endomyocardial biopsy performed to exclude myocarditis is of limited prognostic value in the routine evaluation of dilated cardiomyopathy.

Pregnancy among women with congenitally corrected transposition of great arteries

OBJECTIVES The outcome of pregnancy in congenitally corrected transposition of the great vessels was studied in 22 women. BACKGROUND Women with congenitally corrected transposition of the great vessels often reach childbearing age. Although reports on the outcome of pregnancy in these women are available, the number of patients is small. METHODS The medical and surgical databases at the Mayo Clinic were reviewed, and 36 women >16 years old with congenitally corrected transposition of the great vessels were identified. All of them were contacted, and 22 who had pregnancies were identified and the outcome of pregnancy was evaluated. RESULTS Twenty-two women had 60 pregnancies resulting in 50 live births (83%). Forty-four deliveries (88%) were vaginal and 6 (12%) were by cesarean section. One delivery was premature at 29 weeks. There was one successful twin pregnancy. There were 11 unsuccessful pregnancies. One patient developed congestive heart failure late in pregnancy because of systemic atrioventricular valve regurgitation and required valve replacement in the early postpartum period. One patient had a total of 12 pregnancies, including 1 twin pregnancy and 2 unsuccessful pregnancies. She had multiple pregnancy-related complications, including toxemia, congestive heart failure, endocarditis and myocardial infarction (single coronary artery). No other serious pregnancy-related maternal complications and no pregnancy-related deaths occurred. The mean birth weight of the infants (n = 32) was 3.2 +/- 0.4 kg. None of the 50 live offspring have been diagnosed with congenital heart disease. CONCLUSIONS Successful pregnancy can be achieved in most women with congenitally corrected transposition of the great arteries. The rate of fetal loss and maternal cardiovascular morbidity is increased. Because of the small number of births, the risk of congenital heart disease in offspring of women with congenitally corrected transposition of the great arteries is uncertain.

Premature ventricular contraction-induced cardiomyopathy: a treatable condition.

Premature ventricular contractions (PVCs) are early depolarizations of the myocardium originating in the ventricle. They are often seen in association with structural heart disease and represent increased risk of sudden death,1 yet they are ubiquitous, even in the absence of identifiable heart disease.1,2 They may cause troubling and sometimes incapacitating symptoms such as palpitations, chest pain, presyncope, syncope, and heart failure.3 Traditionally, they have been thought to be relatively benign in the absence of structural heart disease.4,5 Over the last decade, however, PVC-induced cardiomyopathy has been a subject of great interest and the evidence for this entity is rapidly emerging. ### Epidemiology PVCs are common with an estimated prevalence of 1% to 4% in the general population.5 In a normal healthy population, PVCs have been detected in 1% of subjects on standard 12-lead electrocardiography and between 40% and 75% of subjects on 24- to 48-hour Holter monitoring.6 Their prevalence is generally age-dependent,1 ranging from 75 years.8 Commonly thought to be a benign entity,4,5 the concept of PVC-induced cardiomyopathy was proposed by Duffee et al9 in 1998 when pharmacological suppression of PVCs in patients with presumed idiopathic dilated cardiomyopathy subsequently improved left ventricular (LV) systolic dysfunction. Many of these patients often have no underlying structural heart disease and subsequently develop LV dysfunction and dilated cardiomyopathy; in cases of those with an already impaired LV function from underlying structural heart disease, worsening of LV function may occur.10,11 The exact prevalence of PVC-induced cardiomyopathy is not known; it is an underappreciated cause of LV dysfunction, and it is primarily observed in older patients.12 This observation could be due to the fact that the prevalence of …

Diagnosis, Prognosis, and Therapy of Transthyretin Amyloidosis

Transthyretin amyloidosis is a fatal disorder that is characterized primarily by progressive neuropathy and cardiomyopathy. It occurs in both a mutant form (with autosomal dominant inheritance) and a wild-type form (with predominant cardiac involvement). This article guides clinicians as to when the disease should be suspected, describes the appropriate diagnostic evaluation for those with known or suspected amyloidosis, and reviews the interventions currently available for affected patients.

Intracardiac thrombosis and anticoagulation therapy in cardiac amyloidosis.

Background— Primary amyloidosis has a poor prognosis as a result of frequent cardiac involvement. We recently reported a high prevalence of intracardiac thrombus in cardiac amyloid patients at autopsy. However, neither the prevalence nor the effect of anticoagulation on intracardiac thrombus has been evaluated antemortem. Methods and Results— We studied all transthoracic and transesophageal echocardiograms of cardiac amyloid patients at the Mayo Clinic. The prevalence of intracardiac thrombosis, clinical and transthoracic/transesophageal echocardiographic risks for intracardiac thrombosis, and effect of anticoagulation were investigated. We identified 156 patients with cardiac amyloidosis who underwent transesophageal echocardiograms. Amyloidosis was the primary type (AL) in 80; other types occurred in 76 patients, including 56 with the wild transthyretin type, 17 with the mutant transthyretin type, and 3 with the secondary type. Fifth-eight intracardiac thrombi were identified in 42 patients (27%). AL amyloid had more frequent intracardiac thrombus than the other types (35% versus 18%; P=0.02), although the AL patients were younger and had less atrial fibrillation. Multivariate analysis showed that atrial fibrillation, poor left ventricular diastolic function, and lower left atrial appendage emptying velocity were independently associated with increased risk for intracardiac thrombosis, whereas anticoagulation was associated with a significantly decreased risk (odds ratio, 0.09; 95% CI, 0.01 to 0.51; P<0.006). Conclusions— Intracardiac thrombosis occurs frequently in cardiac amyloid patients, especially in the AL type and in those with atrial fibrillation. Risk for thrombosis increased if left ventricular diastolic dysfunction and atrial mechanical dysfunction were present. Anticoagulation therapy appears protective. Timely screening in high-risk patients may allow early detection of intracardiac thrombus. Anticoagulation should be carefully considered.

Intracardiac Thrombosis and Embolism in Patients With Cardiac Amyloidosis

Background— Patients with primary amyloidosis (AL type) have a poor prognosis, in part due to frequent cardiac involvement. Although intracardiac thrombus has been reported in anecdotal cases, neither its frequency nor its role in causing mortality is known. Furthermore, the clinical and echocardiographic variables that may be associated with thromboembolism in cardiac amyloidosis have not been defined. Methods and Results— A total of 116 autopsy or explanted cases of cardiac amyloidosis (55 AL and 61 other type) were identified in the Mayo Clinic. Forty-six fatal nonamyloid trauma cases served as controls. Each heart was examined for intracardiac thrombus. The cause of death was determined from autopsy and clinical notes. Intracardiac thrombosis was identified in 38 hearts (33%). Twenty-three had 1 thrombus, whereas 15 had 2 to 5 thrombi. Although subjects in the AL group were younger and had less atrial fibrillation than those with other types of amyloidosis, the AL group had significantly more intracardiac thrombus (51% versus 16%, P<0.001) and more fatal embolic events (26% versus 8%, P<0.03). Control hearts had no intracardiac thrombus. The presence of both atrial fibrillation and AL was associated with an extremely high risk for thromboembolism (odds ratio 55.0 [95% confidence interval 8.1 to 1131.4]). By multivariate analysis, AL type (odds ratio 8.4 [95% confidence interval 1.8 to 51.2]) and left ventricular diastolic dysfunction (odds ratio 12.2 [95% confidence interval 2.7 to 72.7]) were independently associated with thromboembolism. Conclusions— A high frequency of intracardiac thrombosis was present in cardiac amyloidosis. Furthermore, thromboembolism caused significant fatality. Several risk factors for thromboembolism were identified. Early screening, especially in high-risk patients, and early anticoagulation might reduce morbidity and mortality.

Echocardiographic Improvement Over Time After Cessation of Use of Fenfluramine and Phentermine

OBJECTIVE To determine the echocardiographic changes over time of valvular heart lesions in patients who took the weight loss drugs fenfluramine and phentermine. SUBJECTS AND METHODS This prospective cohort study began at the termination of a randomized, double-blind, placebo-controlled weight loss trial of 18 obese women and 13 obese men (mean age, 42 years; mean body mass index, 33.4 kg/m2) who had been assigned randomly to treatment with fenfluramine and phentermine or to placebo. Echocardiograms were obtained at termination of the trial when fenfluramine was withdrawn from the market and 6 months later. They were interpreted independently by 3 cardiologists blinded to treatment assignment and temporal sequence of the echocardiograms. The main outcome measure was the change in drug-related valvular disease over time. RESULTS One subject assigned to receive the drugs was lost to follow-up, and 3 subjects who did not meet a weight loss goal of 10 kg crossed over from placebo to drug treatment. Echocardiograms were obtained in 19 subjects who received the drugs and 11 subjects who received placebo, and 6-month follow-up echocardiograms were obtained in 15 subjects who received the drugs and 3 who received placebo. Subjects had taken fenfluramine and phentermine a mean of 41 weeks (range, 8-73 weeks). Five of 19 subjects who received the drugs (26%; 95% confidence interval, 7%-46%) and 1 of 11 who received placebo (9%) (odds ratio, 3.6; 95% confidence interval, 0.4-35.6) had findings that met criteria established for drug-related valvular disease. All 5 subjects (4 women and 1 man) receiving the drugs had mild aortic regurgitation, and 1 also had pulmonary hypertension (estimated pulmonary artery pressure, 59 mm Hg). Six months later, the echocardiographic findings had improved in all 5 subjects (P=.06), and 3 no longer met the criteria for drug-related valvular disease. Pulmonary artery pressures decreased to near normal in the subject with pulmonary hypertension (37 mm Hg). Overall, the echocardiographic valvular features improved in 8 of 15 subjects who received the drugs and had echocardiograms performed at both time periods (P=.008). CONCLUSIONS Valvular heart disease did not appear to progress after cessation of use of fenfluramine and phentermine, and echocardiographic valvular features appeared to improve over time.