A Challenging Differential Diagnosis: Distinguishing between Endomyocardial Fibrosis and Apical Hypertrophic Cardiomyopathy.

Endomyocardial fibrosis, which is a cause of restrictive cardiomyopathy, is characterized by the deposition of fibrous tissue in the apical region of 1 or both ventricles. The condition not only affects the diastolic dynamics of the ventricles, but also the function of the atrioventricular valves. The disease occurs predominantly in tropical regions worldwide and in sub-Saharan Africa. This condition is not well understood, with varied manifestations, from subclinical presentations to chronic and progressive edematous syndromes. Here, we present the challenging case of a patient with an indeterminate echocardiographic image, suggesting apical hypertrophy, plus severe aortic stenosis and fibrosis of the left ventricular outflow tract. An electrocardiogram revealed symmetrical T-wave inversion, which is a characteristic manifestation of apical hypertrophy. The importance of cardiac imaging examinations such as echocardiography and cardiac magnetic resonance for differentiating between endomyocardial fibrosis and apical hypertrophy is highlighted in this patient's case.

Minor segmental dyssynergy reflects extensive myocardial damage and global left ventricle dysfunction in chronic Chagas disease.

The majority of patients with Chagas disease (ChD) remain for 10 to 30 years or even for life in the indeterminate form (IF) of this disease. They have positive-specific serology tests for ChD, but no symptoms or physical signs, and normal findings for electrocardiograms (ECGs) and heart, esophagus, and colon radiographs. To investigate whether patients in this phase of disease have any impairment of left ventricular (LV) systolic performance, we assessed their contractility index by the slope of the LV end-systolic pressure-dimension (P(es)-D(es)) relation. We studied 35 patients with ChD (14 IF, 11 digestive form [DF], 10 cardiac form [CF]) and 13 healthy subjects. Patients with the CF had only minor cardiac involvement (bundle-branch block, normal LV ejection fraction). All patients had normal baseline global LV systolic function on 2-dimensional echocardiography, but minor segmental wall motion abnormalities were observed in 3 DF, 3 IF, and 2 CF patients. At rest and during intravenous phenylephrine infusion, we measured LV dimensions by echocardiography, and LV end-systolic pressure was estimated by a calibrated carotid pulse tracing. We also measured percent fractional shortening (%DeltaD) and the rate-corrected mean velocity of fiber shortening (Vcf(c)). Mean values (+/- SD) of %DeltaD and Vcf(c) were not significantly different from those exhibited by healthy control subjects in any of the ChD groups at rest (except for CF) or at peak stress using phenylephrine. The P(es)-D(es) slope was similarly and significantly reduced in all ChD patients (IF: 50.7 +/- 25; DF: 52.3 +/- 24; CF: 60.8 +/- 22 mm Hg/cm) compared with normal subjects (89 +/- 17 mm Hg/cm). The P(es)-D(es) slope was even more depressed (39.6 +/- 10 mm Hg/cm) in ChD patients who had minor segmental wall motion abnormalities (SWMAs) on the baseline 2-dimensional echocardiograph in comparison with the slightly reduced values found in patients with CF who had isolated conduction abnormalities on the ECG (71.8 +/- 10 mm Hg/cm). Although %DeltaD and Vcf(c), even at peak afterload, do not differentiate ChD patients from normal controls, the P(es)-D(es) slope is significantly impaired in IF, DF, and CF patients. The remarkably lower P(es)-D(es) slope value documented in ChD patients exhibiting only minor LVWMAs suggests a more extensive myocardial damage in this group of patients, indicating that they should be considered as exhibiting symptoms of the CF version of the disease.

Ultrasonic tissue characterization for patients with Chagas' disease.

UNLABELLED: This study was undertaken to test the hypothesis that ultrasonic tissue characterization, as evaluated by intensity and cardiac cyclic variation of integrated backscatter (IBS), could identify early myocardial involvement in Chagas' disease. We evaluated 69 participants, age 15 to 73 years (mean +/- SD: 49 +/- 12 years), who were divided as following: 19 control subjects; 13 patients with the indeterminate form of Chagas' disease; 7 patients with the digestive form; and 30 patients with the cardiac form. IBS images were obtained in parasternal short-axis (basal, papillary muscle, apical) view and analyzed in 12 left ventricular (LV) segments (anterior, lateral, posterior, and septal). The following IBS variables were evaluated: (1) the corrected coefficient (CC) of IBS, obtained by dividing IBS intensity, in each cardiac segment, by IBS intensity measured in a rubber phantom using the same equipment adjustments at the same depth; and (2) magnitude of cardiac cyclic variation (MCV) of IBS, as measured by the peak-to-peak difference between maximal and minimal values of IBS in cardiac cycle. The CC of IBS was increased (P <.05) for patients with the cardiac form who had LV segments with normal wall motion as compared with control subjects, in 4 of 12 segments evaluated (basal anterior, midposterior and midseptal, anterior apical), whereas the remaining chagasic groups were comparable with controls subjects. The CC of IBS tended to increase with worsening of LV segmental wall motion. MCV showed a large individual variability and had a large mean value (P <.05) in just 1 of 12 segments evaluated, when patients with the cardiac form were compared with control subjects. No correlation was observed between the magnitude of LV dysfunction and MCV of IBS. IN CONCLUSION: (1) the CC of IBS was able to provide early differentiation of cardiac involvement for patients with Chagas' disease who had LV segments with normal wall motion; (2) increase of CC of IBS with worsening of LV segmental wall motion suggests a relationship between the acoustic properties of myocardial tissue and grading of myocardial fibrosis; (3) MCV was not able to differentiate patients with Chagas' disease from control subjects; and (4) patients with the indeterminate form of Chagas' disease were not differentiated from control subjects by any of the IBS techniques evaluated in this study.

Left ventricular global performance and diastolic function in indeterminate and cardiac forms of Chagas' disease.

The majority of patients with Chagas' disease remain for 10 to 30 years in the indeterminate form (IF) of this disease. They have no symptoms, serologic positivity, normal electrocardiogram results and heart size, and normal left ventricular global and segmental systolic function on 2-dimensional echocardiography. To investigate whether this group of patients have any impairment of left ventricular global performance (Tei index) and diastolic function, we have studied 43 individuals (age 49 +/- 12 years) including 14 healthy volunteers and 29 patients with Chagas' disease divided as IF (n = 12) and cardiac form (n = 17). Echocardiographic measurements included ejection fraction, Tei index, left atrial volume index, transmitral (peak early transmitral flow velocity, late peak mitral velocity, tissue Doppler, late peak mitral velocity duration) and pulmonary (systolic pulmonary vein velocity, diastolic pulmonary vein velocity, retrograde pulmonary vein velocity, retrograde pulmonary vein velocity duration) flow velocities, and tissue Doppler velocities at lateral mitral annulus (peak early transmitral flow velocity, late peak mitral velocity, systolic pulmonary vein velocity). Although ejection fraction and S' velocity were significantly lower for patients with cardiac form compared with control and IF groups, Tei index was not able to differentiate patients with cardiac conditions from the other groups. Diastolic dysfunction was documented for patients with cardiac form by left atrial volume index, early transmitral peak velocity, early expansion wave by tissue Doppler, late expansion wave by tissue Doppler, and peak early transmitral flow velocity/early expansion wave by tissue Doppler. Patients with the IF of Chagas' disease did not show any abnormality of diastolic function. Thus, when the IF is further characterized on the basis of absence of any echocardiographic marker of regional systolic dysfunction, no impairment of diastolic function can be detected.

Prediction of left ventricular wall motion recovery after acute myocardial infarction by Tl-201 gated SPECT: incremental value of integrated contractile reserve assessment.

BACKGROUND: This investigation tested the application of low-dose dobutamine (LDD) gated single photon emission computed tomography (SPECT) with thallium 201 for myocardial viability detection early after acute myocardial infarction (AMI). METHODS AND RESULTS: Thirty-two hemodynamically stable post-AMI patients (aged 55 +/- 5 years [mean +/- SEM]; 20 men) who were exhibiting regional left ventricular dysfunction underwent stress-redistribution Tl-201 scanning within 4 to 8 days, followed by 2 additional gated SPECT acquisitions after Tl-201 reinjection, at rest and during LDD. A visual 5-point score was computed for segmental radiotracer uptake (0, normal; 4, absent) and a 4-point score for left ventricular wall motion (1, normal; 4, dyskinesis). Predominant viable myocardium in dyssynergic regions was predicted by a mean Tl-201 uptake score of 2 or less or ischemic area of 30% or greater. These indices showed a significant association with wall motion improvement in follow-up echocardiographic studies (overall accuracy = 0.69, sensitivity = 0.93, and specificity = 0.50). Regarding the response to LDD stimulus, an increase in mean wall motion score of 30% or greater was predictive of predominant viable myocardium. Contractile reserve assessment yielded a significant increment in the predictive accuracy for function recovery (overall accuracy = 0.84, sensitivity = 0.71, and specificity = 0.94). CONCLUSIONS: Evaluation of contractile reserve by means of LDD gated SPECT with Tl-201 is safely feasible early after AMI, with incremental value over perfusion assessment alone for myocardial viability detection.