Relationship between left ventricular twist and circulating biomarkers of collagen turnover in hypertensive patients with heart failure.

BACKGROUND: Left ventricular (LV) twist may be a compensatory mechanism to preserve ejection fraction (EF). In patients with hypertension, twist varies depending on the left ventricle's degree of remodeling and systolic function; it is increased in those with hypertension with normal EF (HTNEF) and diminished in those with hypertension with low EF (HTLEF). The ratio of collagen-degradation biomarkers in patients with hypertension is higher in those with low EFs than those with preserved EFs and may contribute to remodeling and systolic dysfunction. METHODS: The aim of this study was to evaluate the relationship between these biomarkers and LV twist in 82 patients with hypertension, 41 with EFs < 50% (HTLEF group) and 41 with EFs ≥ 50% (HTNEF group). Net LV twist was measured using speckle-tracking echocardiography. Markers of collagen turnover, including serum concentrations of matrix metalloproteinase-1 (MMP1), tissue inhibitor of MMP1 (TIMP1), and the ratio of MMP1 to TIMP1, were measured. RESULTS: Log TIMP1, log MMP1, and log MMP1/TIMP1 ratio levels were higher in the HTLEF group than the HTNEF group (12.3 ± 0.3 vs 11.8 ± 0.1 [P < .0001], 9.1 ± 0.3 vs 8.0 ± 0.2 [P < .0001], and -3.3 ± 0.3 vs -3.8 ± 0.2 [P < .0001], respectively). Net LV twist was lower in the HTLEF group than the HTNEF group (3.3 ± 1.1 vs 11.7 ± 0.7, P < .0001). An inverse correlation existed between log MMP1/TIMP1 and net LV twist after adjusting for age, EF, duration of heart failure, systolic blood pressure, LV mass index, and LV sphericity index at end-diastole (r = -0.43, P < .0001). CONCLUSIONS: This inverse correlation between twist and loss of myocardial collagen scaffolding in patients with hypertension with heart failure suggests that the integrity of the extracellular matrix may play an important role in preserving myocardial deformation.

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.

Time to twist: marker of systolic dysfunction in Africans with hypertension.

AIMS: Speckle-tracking echocardiography (STE) has emerged as a quantitative technique to assess left ventricular (LV) function via twist mechanics. Hypertension-associated changes in LV twist have not been previously evaluated in African patients with LV systolic dysfunction. This study evaluates LV twist dynamics in hypertensive patients with a low ejection fraction (EF). METHODS AND RESULTS: Forty-one hypertensive patients with EF <45% and normal coronary angiography (HTLEF group) were compared with 41 control subjects using STE. Peak apical rotation (AR) and isochronous basal rotation (BR) were measured, as was net twist (maximal value of simultaneous AR-BR). Rigid body rotation (RBR) was defined as AR and BR occurring in the same direction. Of 41 HTLEF patients, 28 (68%) had normal twist pattern, whereas 13 (32%) exhibited RBR; 11 of those 13 exhibited clockwise rotation. AR (1.89° ± 0.99 vs. 7.15° ± 2.26; P < 0.0001), BR (1.44° ± 0.78 vs. -3.75° ± 1.61; P < 0.0001), and net twist (3.3° ± 1.17 vs. 10.9° ± 2.7; P < 0.0001) were lower in HTLEF patients. The subgroup with clockwise RBR showed greater LV dysfunction (EF: 27.9 ± 5.8 vs. 35 ± 7.5%; P = 0.005) and more spherical LV geometry in both diastole and systole (P = 0.0009 and P = 0.0002, respectively) compared with those who had a normal pattern of twist. In the HTLEF subgroup with normal twist pattern, AR (r = 0.57; P = 0.002) and net twist (r = 0.57; P = 0.002) correlated with EF. CONCLUSIONS: LV twist in patients with hypertension and EF <45% is diminished. Apical rotation and net twist are good correlates for EF in hypertensive patients with EF <45%.

Left ventricular twist in a normal African adult population.

AIMS: Speckle tracking has emerged as a quantitative technique for assessing left ventricular (LV) function. However, no normative data for LV twist using speckle tracking echocardiography (STE) are available in the black population. This study assessed myocardial mechanics by determining LV twist parameters in different age groups using STE, and evaluated the effect of ageing on LV twist in this population. METHODS AND RESULTS: The study population consisted of 127 healthy volunteers divided into four age groups: 20-29 (n = 34); 30-39 (n = 33); 40-49 (n = 29); and 50-65 (n = 31) years. Parasternal short-axis images of three consecutive end-expiratory cardiac cycles at LV basal, papillary muscle, and apical levels, and apical four-chamber images were obtained. Apical and (AR) basal (BR) LV peak systolic rotation during ejection and instantaneous LV peak systolic twist (net twist, defined as maximal value of instantaneous AR minus BR) were measured. Mean strain values were -17.28 ± 3.30% for longitudinal, -17.40 ± 3.29% for circumferential, and 57.49 ± 3.32% for radial strain. Mean rotational values were AR (5.56 ± 1.98°), BR (-3.31 ± 0.92°), and net twist (8.87 ± 2.21°). AR, BR, and net twist increased with age, whereas longitudinal, circumferential, and radial strain decreased with age. Multivariate linear regression analysis showed age as the main predictor of net twist (R(2) = 0.82, P < 0.0001). CONCLUSION: These data establish values for strain and twist in a normal black adult population. Net twist increases with age, whereas strain parameters decrease. Age is the strongest independent predictor of LV twist.

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.