A case of mitochondrial disease with severe left ventricular hypertrophy

A 35-year-old woman was admitted for progressive dyspnea with lower limb edema. Transthoracic echocardiography showed severe left ventricular hypertrophy (LVH) and heart failure with preserved ejection fraction (HFPEF). Electron microscopy of an endomyocardial biopsy sample revealed a high density of mitochondria of abnormal size and shape. We report a case of mitochondrial disease with severe LVH and HFPEF.     

基于心腔内超声造影测量左心室肥厚患者室壁厚度

目的 采用左心室腔内超声造影(LVO)改善心内膜显影,评价LVO诊断左心室心肌肥厚的价值。方法 选择经常规超声心动图检查不能清晰显示并测量左心室壁厚度的患者66例,测量造影前后室间隔、左心室侧壁基底段、中间段及心尖段的室壁厚度,并用Bland-Altman法分析观察者内和观察者间的一致性。结果 LVO后,65例(98.48%,65/66)心内膜边缘的清晰程度明显改善,易于测量室壁厚度。LVO测定的室壁厚度与常规超声心动图所测厚度的差异有统计学意义(P<0.05)。常规超声与LVO测量的室壁厚度相符仅31个节段。Bland-Altman法分析显示,左心室壁厚度测LVO值的观察者内和观察者间的一致性较好。结论 LVO能够通过增进左心室腔的显影,改善心内膜边缘的清晰度,有利于准确测定心肌厚度。     

Physiologic cardiac hypertrophy corrects contractile protein abnormalities associated with pathologic hypertrophy in rats.

To evaluate the combined effects of cardiac overload imposed by hypertension and by chronic exercise, male and female rats were made hypertensive by unilateral renal artery stenoses and made to exercise in an 8-10-wk swimming program. Sedentary normotensive animals, sedentary hypertensive animals and normotensive animals exposed to the swimming program were also studied. Hypertension was associated with the development of cardiac hypertrophy, and this was exaggerated in hypertensive swimmers. Actomyosin, Ca2+-myosin, and actin-activated Mg2+-myosin ATPase activities were enhanced in normotensive swimmers, depressed in hypertensives and were normal or increased in hypertensive swimmers. Myosin isoenzyme analysis showed a predominant V1 pattern in normals; an increase in percent V1 isoenzyme is swimmers; a predominant V3 pattern in hypertensives; and a return to the predominant V1 pattern in hypertensive swimmers. These findings suggest that the hypertrophy imposed by hypertension and hypertrophy imposed by physical training using a chronic swimming program are distinctly different biological phenomena. Physical training by swimming prevents the changes in cardiac myosin induced by hypertension despite the exaggeration of hypertrophy.     

Atrial natriuretic peptide gene promoter polymorphism is associated with left ventricular hypertrophy in hypertension

Recent studies suggest that the ANP (atrial natriuretic peptide)/NPRA (type A natriuretic peptide receptor) system modulates ventricular remodelling and cardiac hypertrophy in hypertension in Western populations. In the present study, we tested for any association between two SNPs (single nucleotide polymorphisms) in the ANP gene (one in the promoter and one exonic) with cardiac hypertrophy. We tested the hypothesis in 2118 hypertensive patients, including 945 with LVH [LV (left ventricular) hypertrophy] and 1173 without LVH, as well as 816 healthy control subjects. All subjects were genotyped for the -A2843G and A188G polymorphisms. We found that the GG genotype at position -2843 conferred a 2.2-fold risk for LVH compared with the AA or AG genotypes, including septal wall thickness (11.8+/-1.4 mm for GG compared with 10.9+/-1.4 and 10.7+/-1.3 mm for AA and AG respectively; P<0.01), posterior wall thickness (11.8+/-2.8 mm for GG compared with 10.6+/-1.2 and 10.6+/-1.4 mm for AA and AG respectively; P<0.01), LV mass index (62.7+/-13.6 g/m(2.7) for GG compared with 57.9+/-8.6 and 57.8+/-8.4 g/m(2.7) for AA and AG respectively; P<0.05) and relative wall thickness (50.7+/-10.8% for GG compared with 44.3+/-7.3 and 43.5+/-6.8% for AA and AG respectively; P<0.05). Plasma levels of ANP were significantly lower in the hypertensive patients with LVH carrying the GG genotypes compared with those carrying the AA or AG genotypes (P<0.01). No association of GG genotype with echocardiographic variables and plasma ANP levels was identified in hypertensive patients without LVH and in control subjects (P>0.05). No significant association between the A188G genotype and echocardiographic variables was found in either hypertensive patients or controls (P>0.05). In conclusion, our findings indicate that the -A2843G polymorphism in the ANP gene promoter might be a genetic risk factor for the development of LVH in patients with hypertension.     

实时三平面应变率成像评价原发性高血压左心室心肌肥厚对长轴舒张功能的影响

目的：应用实时三平面应变率成像技术定量评价原发性高血压患者左心室肥厚的长轴舒张功能。方法：选择原发性高血压患者62例和正常对照组35例。原发性高血压患者分成两组,30例伴有心肌肥厚,32例没有心肌肥厚。应用实时三平面应变率成像技术测定各受检者左心室各壁基底段及中间段舒张早期峰值应变率（SRe）、舒张晚期峰值应变率（SRa）。结果：左室壁基底段、中间段SRe在原发性高血压组均明显小于正常对照组（P〈0.01）,且原发性高血压左室肥厚（LVH）组均明显小于非左室肥厚（NLVH）组（P〈0.05或P〈0.01）。SRa在左室侧壁和后壁LVH组小于正常对照组（P〈0.05）。结论：实时三平面应变率成像能够准确定量分析原发性高血压患者左心室肥厚长轴舒张功能的变化。     

FGF23 induces left ventricular hypertrophy

Chronic kidney disease (CKD) is a public health epidemic that increases risk of death due to cardiovascular disease. Left ventricular hypertrophy (LVH) is an important mechanism of cardiovascular disease in individuals with CKD. Elevated levels of FGF23 have been linked to greater risks of LVH and mortality in patients with CKD, but whether these risks represent causal effects of FGF23 is unknown. Here, we report that elevated FGF23 levels are independently associated with LVH in a large, racially diverse CKD cohort. FGF23 caused pathological hypertrophy of isolated rat cardiomyocytes via FGF receptor-dependent activation of the calcineurin-NFAT signaling pathway, but this effect was independent of klotho, the coreceptor for FGF23 in the kidney and parathyroid glands. Intramyocardial or intravenous injection of FGF23 in wild-type mice resulted in LVH, and klotho-deficient mice demonstrated elevated FGF23 levels and LVH. In an established animal model of CKD, treatment with an FGF-receptor blocker attenuated LVH, although no change in blood pressure was observed. These results unveil a klotho-independent, causal role for FGF23 in the pathogenesis of LVH and suggest that chronically elevated FGF23 levels contribute directly to high rates of LVH and mortality in individuals with CKD.     

Late ventricular potentials in left ventricular hypertrophy in patients with stage-II hypertension

AIM: To evaluate diagnostic significance of high-resolution ECG in patients with blood hypertension (BH) stage II with left ventricular hypertrophy (LVH) in the presence or absence of angiographically verified atherosclerosis of the coronary arteries. MATERIALS AND METHODS: ECG (registration of late ventricular potentials by M. Simson and R. Haberl), echo-CG and coronaroventriculography were performed in 63 males with BH stage II. RESULTS: Late ventricular potentials (LVP) were detected according to M. Simson in 6.3% of the examinees, while according to R. Haberl in none of them. Duration of filtered complex QRS was normal in all the patients. LVP characteristics were not significantly different in the presence or absence of coronary atherosclerosis. Severe and moderate LVH patients differed significantly by duration of low-amplitude high-frequency signals. An inverse correlation existed between duration of low-amplitude signals in the end of filtered complex QRS and parameters of echo-CG. CONCLUSION: LVP registration both by M. Simson and R. Haberl failed to provide additional information on substrate of the arrhythmia in hypertension stage II patients with LVH free of clinical symptoms of tachyarrhythmia. However, there is an inverse correlation between duration of low-amplitude signals in the end of filtered complex QRS and thickness of interventricular septum, asymmetry index, left ventricular myocardial mass.     

Hypertension: left ventricular hypertrophy, ventricular ectopy, and sudden death.

Left ventricular hypertrophy (LVH) has been identified as a significant risk factor for future cardiovascular morbidity and mortality. LVH and its sequelae such as myocardial ischemia, impaired filling and contractility, ventricular arrhythmias, and congestive heart failure can be reduced by specific antihypertensive agents. Future clinical trials will determine whether a reduction of LVH will ultimately improve its inherent ominous prognosis.     

高血压病伴左心室肥厚的血液流变学观察——附89例报告

目的：探讨高血压病伴左心室肥厚患者的血液流变学改变及其临床意义。方法：将高血压病伴左心室肥厚患者８９例作为Ａ组;单纯高血压不伴左心室肥厚患者作为Ｂ组,检测的两组的血液流变学变化并将结果加以比较。结果：Ａ组的血黏度,红细胞压积,红细胞沉降率显著高于Ｂ组。结论高血压患者的血黏度增高是其形成左心室肥厚的重要影响因素。对高血压病患者除予积极降压外,还应给予适当的降低血黏度治疗。     

Plasma adiponectin levels are associated with left ventricular hypertrophy in a random sample of middle-aged subjects

Abstract

Background. A low adiponectin level is associated with high blood pressure which, in turn, often results in left ventricular hypertrophy. We evaluated the association between plasma adiponectin concentrations and echocardiographic measurements, including left ventricular mass index (LVMI), in 933 middle-aged subjects consisting of 453 hypertensives and 480 controls.

Methods. Plasma adiponectin concentrations were measured with an enzyme-linked immunosorbent assay (ELISA) method. One experienced cardiologist performed echocardiographic examinations, and LVMI was calculated according to Devereux’s method.

Results. Low plasma adiponectin levels were independently associated with increased intraventricular septum thickness, posterior ventricular wall thickness, and left ventricular mass index (P<0.001) in the whole cohort. In the subgroup analysis, the association between these echocardiographic parameters and adiponectin concentrations was observed only in the hypertensive cohort although fractional shortening revealed an association with adiponectin levels also in the control cohort (P=0.021). Findings remained significant after adjustment for the major risk factors for LVMI, such as age, sex, smoking, and systolic blood pressure.

Conclusions. This study in a large population sample detected an association between low plasma adiponectin concentration and LVMI, a marker of left ventricular hypertrophy. This association may be one of the factors that could explain the reported increased cardiovascular risk in subjects with low adiponectin levels.     

Echo doppler assessment of left ventricular function in rats with hypertensive hypertrophy.

OBJECTIVE: This study attempted to establish echocardiographic measurements of left ventricular (LV) mass and LV systolic and diastolic function, particularly in rats with hypertensive heart. METHODS: M-mode LV echograms and Doppler mitral flow were obtained in Dahl salt-sensitive rats placed on 0.3% or 8% sodium chloride diet. Echo Doppler measurements were compared with catheterization and pathologic measurements in 54 rats for LV mass and in 45 rats for LV systolic and diastolic function. RESULTS: Echocardiographic measurement of LV mass correlated well with pathologic measurement (r = 0.94, P <.01, n = 54, SEE = 0.08 mg), independent of LV size, aging, and therapeutic intervention. Endocardial fractional shortening (FS) correlated with LV peak + dP/dt (r = 0.56, n = 45, P <.01), and the correlation was improved to r = 0.71 if 11 rats with marked LV hypertrophy were excluded. Midwall FS correlated well with LV peak + dP/dt (r = 0.72, n = 45, P <.01) even if rats with extremely thickened ventricular wall were included. If midwall FS was lower than 14%, LV systolic dysfunction was very likely (sensitivity 67%, specificity 91%). Association of mitral E/A ratio of 2.0 or greater with deceleration time of shorter than 35 ms was an accurate indicator of elevated LV end-diastolic pressure (sensitivity 82%, specificity 86%) and increased lung weight because of congestive heart failure (sensitivity 89%, specificity 96%) in rats with hypertension. CONCLUSION: LV mass, LV systolic function, and LV end-diastolic pressure were assessable with echo Doppler in rats with hypertensive heart.     

厄贝沙坦对左室肥厚及左室舒张功能影响的观察

目的采用超声心动图技术观察厄贝沙坦对左室肥厚及左室舒张功能的影响,以期为临床寻找能逆转左室肥厚、改善左室舒张功能的有效药物。方法选择经超声心动图检查确诊为左室肥厚的高血压患者50例,在停用其他降压药1周后,服用厄贝沙坦,维持用药20周,每天测血压2次;治疗前后由专人进行超声心动图检查。结果 50例患者治疗后血压平均下降(14.2±7.2)mmHg/(7.9±3.8)mmHg(P<0.01);治疗后与治疗前比较,左室舒张功能改善,差异有统计学意义(P<0.01)。结论厄贝沙坦不仅24h平稳降压,且可逆转左室肥厚、改善左室舒张功能,副作用少,是临床可取的降压药。