Prevalence and significance of isolated left ventricular non-compaction phenotype in normal black Africans using echocardiography.

BACKGROUND: Several large, prospective screening studies of predominantly Caucasian patients have suggested that hypertrabeculation may not necessarily be pathologic unless there is concomitant left ventricular (LV) dysfunction, LV dilatation, history of arrhythmia, family history, or characteristic gene mutations. This conundrum may be magnified in blacks, in whom hypertrabeculation and LV hypertrophy is more common. We therefore investigated the frequency of hypertrabeculation/isolated LV noncompaction (ILVNC) phenotype in normal black Africans and evaluated LV function using sensitive measures of deformation and twist. METHODS: Two hundred and fifty-three volunteers were recruited and evaluated according to strict inclusion and exclusion criteria. Their mean age was 36.3 ± 12.2 years. RESULTS: Trabeculations were found in 12 (4.74%) participants. Three (1.2%) subjects had ≥ 4 LV trabeculations. The LV apex was the most common anatomical site for the location of trabeculations. Subjects with trabeculations were more likely to be males of a younger age, and had greater LV end-diastolic and end-systolic parameters and lateral e'. However, 0.8% of the population fulfilled the Stollberger criteria, and none fulfilled the Jenni, Milwaukee, or Baragwanath criteria. All subjects in this study had normal rotation patterns with no differences in rotational parameters or net twist. CONCLUSIONS: Trabeculations may be found as a normal variant in black Africans. Assessing trabeculations alone may infer ILVNC; however, utilizing the more comprehensive ILVNC criteria enables differentiation of a possible LVNC phenotype. Normal individuals with hypertrabeculation have normal LV function and normal rotation patterns, with no differences in rotational parameters or net twist.

Echocardiographic Indices of the Left and Right Heart in a Normal Black African Population.

BACKGROUND: It is unknown whether ethnic differences occur with regard to right heart echocardiographic parameters. The aim of this study therefore was to establish normative values of left and right heart parameters in a black African population and to evaluate the effect of age and body mass index (BMI) on specific right ventricle (RV) parameters. METHODS: Two hundred fifty-three normal subjects were prospectively studied. A standardized echocardiographic examination was conducted with the RV focused view used to derive RV measurements. All left and right heart measurements were made in accordance with the American Society of Echocardiography 2015 chamber guideline recommendations. Right ventricle free wall strain was assessed using an RV focused apical four-chamber view. RESULTS: The average age was 36.3 ± 12.2 years, and 59% of patients were female. The mean left ventricular ejection fraction was 62.3% ± 5.7%. The RV linear measurements (RV base, 31.0 ± 4.5 mm; midcavity, 26.3 ± 5.8 mm) were not associated with sex, age, or BMI except for the RV length (64.6 ± 8.9 mm), which was greater in male patients. Tricuspid annular plane systolic excursion (TAPSE) was 21.7 ± 2.8 mm, fractional area change was 42.1% ± 5.5%, tricuspid annular peak systolic velocity RV S' was 12.1 ± 1.9 m/sec, and RV free wall strain was -31.5% ± 8.6%. Age and BMI were not associated with right atrial (RA) volumetric measurements, RV linear measurements, or any RV functional parameters except TAPSE and RV A', which increased with BMI. CONCLUSIONS: This study establishes normal left and right heart parameters in a black African population. Aging was not associated with RA or RV parameters except for RV E' and A'. BMI does not affect RA/RV measurements but may cause variability in TAPSE and RV A'.

Clinical outcomes in patients with isolated left ventricular noncompaction and heart failure.

BACKGROUND: We prospectively evaluated long-term clinical outcomes of patients diagnosed with isolated left ventricular noncompaction (ILVNC) and heart failure from a sub-Saharan African population. METHODS AND RESULTS: Patients in this single-center study were followed at a tertiary care institution. Clinical follow-up was performed with the use of protocol-driven echocardiographic screening for ventricular thrombus every 4 months. Warfarin was maintained or initiated only if thrombus was detected with the use of echocardiography. Fifty-five patients were followed for 16.7 ± 5.9 (range 12-33) months. All individuals had left ventricular (LV) ejection fraction <50% (mean 29.6 ± 11.8%). Of the 55 patients, 7 (12.7%) died, and sudden cardiac death was the cause in 5 (71.4%). There were no differences in baseline clinical, echocardiographic, or electrocardiographic characteristics between survivors and nonsurvivors. Recurrent heart failure developed in 12 patients (21.8%); 1 patient developed a ventricular arrhythmia. No thromboembolic or major bleeding complications occurred in the 16 patients on warfarin; 1 episode of thromboembolism occurred in the 39 patients not on warfarin. Mean survival probability at 33 months was 0.64. CONCLUSIONS: Sudden cardiac death was the most common cause of death in patients with ILVNC and heart failure. Recurrent heart failure occurred in 21.8% of patients. Development of LV thrombus and cardioembolism is uncommon in this population.

Left ventricular twist in left ventricular noncompaction.

AIMS: Left ventricular (LV) twist is an important component of systolic function. The effect of abnormal LV twist on adverse remodelling of the heart in left ventricular noncompaction (LVNC) is unknown. This study used speckle-tracking echocardiography to evaluate LV twist in patients with LVNC and determine whether abnormal LV twist is associated with more adverse LV remodelling. METHODS AND RESULTS: Clinical, echocardiographic, and myocardial deformation characteristics were prospectively compared between 60 subjects diagnosed with LVNC and 59 age-matched healthy controls. Net instantaneous twist was defined as: peak apical rotation minus isochronous basal rotation. Normal rotation during systole was defined based on the 2010 ASE/EAE consensus document. Rigid body rotation (RBR) was determined present if the apex and base moved in the same direction during ejection. Rigid body rotation was found in 32 (53.3%) subjects with LVNC. The 28 subjects with LVNC and normal LV rotation had diminished apical rotation, basal rotation, and net twist compared with normal controls (P < 0.0001). Patients with LVNC and RBR had worse NYHA functional status (P < 0.0001), but similar echocardiographic indices of remodelling, ejection fraction, and strain parameters as those with LVNC and normal LV rotation. CONCLUSION: Left ventricular twist is diminished in subjects with LVNC and normal LV rotation. Rigid body rotation occurs in 53.3% of subjects with LVNC and is not associated with more adverse remodelling than subjects with LVNC and normal LV rotation.

Isolated left ventricular noncompaction in identical twins.

The investigators describe 35-year-old monozygotic twins who presented 6 months apart with heart failure. In conclusion, this is the first report of adult monozygotic twins with isolated left ventricular noncompaction who presented with similar clinical and echocardiographic features and abnormal twist mechanics.

Isolated left ventricular noncompaction in sub-Saharan Africa: a clinical and echocardiographic perspective.

BACKGROUND: Isolated left ventricular noncompaction (ILVNC) is a cardiomyopathy caused by intrauterine failure of the myocardium to compact. Common clinical complications are heart failure, arrhythmias, and cardioembolism. A paucity of data exists relating to clinical and echocardiographic features of ILVNC in Africans. METHODS AND RESULTS: This study is a single-center, prospective case-control study, whereby subjects attending a dedicated cardiomyopathy clinic were screened for and diagnosed with ILVNC, provided they had no other associated structural heart disease and fulfilled all the accompanying echocardiographic criteria: (1) end-systolic ratio of noncompacted layer to compacted layer >2, (2) presence of >3 prominent apical trabeculations, and (3) deep intertrabecular recesses that fill with blood from the ventricular cavity visualized using color Doppler ultrasound. Fifty-four subjects were identified, age 45.4±13.1 years (mean±SD), 95% confidence interval 3.6 to 10.2, 55.6% male, and 63.0% New York Health Association Class II, and prevalence of LVNC in our clinic was 6.9%, 95% confidence interval 3.6 to 10.2. Heart failure because of systolic dysfunction was the most common clinical presentation (53 subjects, 98.1%). Left ventricular end-diastolic diameter was 61.4±7.2 mm (mean±SD) and ejection fraction 26.7±11.9% (mean±SD). Common sites of noncompaction were the apical (100%), midinferior (74.1%), and midlateral (64.8%) walls. Right ventricular noncompaction occurred in 12 subjects (22.2%). Pulmonary hypertension was documented in 45 cases (83.3%). Right ventricular dilation was noted in 40 subjects (74.1%), while right ventricular function was depressed in 32 (59.3%). Tricuspid S' was 9.6±2.8 cm/s (mean±SD). No echocardiographic features suggestive of ILVNC were noted in a healthy control group of African descent. CONCLUSIONS: ILVNC in patients of African descent can be characterized by biventricular abnormality and pulmonary hypertension, in addition to isolated left-sided abnormality.