Measurement of left ventricular mass: methodology and expertise

Empowering Lower Limb Disorder Identification through PoseNet and Artificial Intelligence

A novel approach is presented in this study for the classification of lower limb disorders, with a specific emphasis on the knee, hip, and ankle. The research employs gait analysis and the extraction of PoseNet features from video data in order to effectively identify and categorize these disorders. The PoseNet algorithm facilitates the extraction of key body joint movements and positions from videos in a non-invasive and user-friendly manner, thereby offering a comprehensive representation of lower limb movements. The features that are extracted are subsequently standardized and employed as inputs for a range of machine learning algorithms, such as Random Forest, Extra Tree Classifier, Multilayer Perceptron, Artificial Neural Networks, and Convolutional Neural Networks. The models undergo training and testing processes using a dataset consisting of 174 real patients and normal individuals collected at the Tehsil Headquarter Hospital Sadiq Abad. The evaluation of their performance is conducted through the utilization of K-fold cross-validation. The findings exhibit a notable level of accuracy and precision in the classification of various lower limb disorders. Notably, the Artificial Neural Networks model achieves the highest accuracy rate of 98.84%. The proposed methodology exhibits potential in enhancing the diagnosis and treatment planning of lower limb disorders. It presents a non-invasive and efficient method of analyzing gait patterns and identifying particular conditions.

Cardiac computed tomography-derived coronary artery volume to myocardial mass

In the absence of disease impacting the coronary arteries or myocardium, there exists a linear relationship between vessel volume and myocardial mass to ensure balanced distribution of blood supply. This balance may be disturbed in diseases of either the coronary artery tree, the myocardium, or both. However, in contemporary evaluation the coronary artery anatomy and myocardium are assessed separately. Recently the coronary lumen volume to myocardial mass ratio (V/M), measured noninvasively using coronary computed tomography angiography (CTCA), has emerged as an integrated measure of myocardial blood supply and demand in vivo. This has the potential to yield new insights into diseases where this balance is altered, thus impacting clinical diagnoses and management. In this review, we outline the scientific methodology underpinning CTCA-derived measurement of V/M. We describe recent studies describing alterations in V/M across a range of cardiovascular conditions, including coronary artery disease, cardiomyopathies and coronary microvascular dysfunction. Lastly, we highlight areas of unmet research need and future directions, where V/M may further enhance our understanding of the pathophysiology of cardiovascular disease.

Maternal Factors in Pregnancy and Ethnicity Influence Childhood Adiposity, Cardiac Structure, and Function

IMPORTANCE

The links between maternal and offspring adiposity and metabolic status are well established. There is much less evidence for the impact of these relationships combined with ethnic background on cardiac structure and function in childhood.

OBJECTIVE

To test the hypothesis that ethnicity, maternal adiposity and glycemic status, and child adiposity affect cardiac structure and function.

DESIGN

A prospective cohort study.

SETTING

A single-center mother-child cohort study. The cohort is a subset of the international multi-center Hyperglycemia and Adverse Pregnancy Outcomes (HAPO) study.

PARTICIPANTS

This study included 101 healthy pre-pubertal British-born children [56 White Europeans (WEs) and 45 South Asians (SAs)] with a median age of 9.1 years, range 6.0-12.2 years, at the time of the investigation.

MAIN OUTCOMES AND MEASURES

Anthropometric and echocardiographic measurements were made on the cohort. Maternal pregnancy and birth data were available. Relationships between maternal parameters (BMI and glucose status), child adiposity, and echo measures were assessed.

RESULTS

Despite no ethnic difference in BMI SDS at a median age of 9.1 years, SA children exhibited higher levels of body fat than WE children (whole body, right arm, and truncal fat all p < 0.001). SA children also exhibited greater changes in weight and height SDS but not BMI SDS from birth than WE children. As expected, maternal BMI correlated with child BMI (r = 0.28; p = 0.006), and body fat measures (e.g., whole body fat r = 0.25; p = 0.03). Maternal fasting glucose levels were associated with child body fat measures (r = 0.22-0.28; p = 0.02-0.05). Left ventricular (LV) indices were not different between SA and WE children, but E/A and E'/A' (measures of diastolic function) were lower in SA when compared with WE children. LV indices correlated positively to BMI SDS and body fat markers only in SA children. Maternal fasting and 2-h glucose were negatively correlated with E'/A' in SA children (r = -0.53, p = 0.015, and r = -0.49, p = 0.023, respectively) but not in WE children.

CONCLUSION AND RELEVANCE

SA and WE children exhibit differences in adiposity and diastolic function at a median age of 9.1 years. Novel relationships between maternal glycemia, child adiposity, and cardiac structure and function, present only in SA children, were identified.

Visceral fat level correction of the left ventricular hypertrophy electrocardiographic criteria

Background

Left ventricular hypertrophy (LVH) is a well‐known risk factor for cardiovascular events. Even though there are many electrocardiographic (ECG) criteria for LVH, they still provide poor performance, especially among obese patients. The aim of this study was to examine whether adding visceral fat to ECG LVH criteria improves accuracy in the diagnosis.

Methods

One thousand seven hundred twenty two patients were included in the study. All patients underwent a complete physical examination, office blood pressure measurement, analysis of body composition, 12‐lead ECG, and M‐mode two‐dimensional echocardiography. Four standard ECG criteria for LVH were analyzed, including Cornell voltage criteria, Cornell duration criteria, Sokolow–Lyon voltage criteria, and Sokolow–Lyon product criteria. Adjustments of ECG LVH criteria were performed using visceral fat level (VFATL) and BMI. Transthoracic echocardiography was used as a reference method to compare the quality of ECG LVH criteria.

Results

Multivariate logistic regression models were created and revealed a significant increase of area under curve (AUC) after VFATL and BMI addition to ECG LVH criteria. Improvement of sensitivity at 90% specificity was observed in all created models. The odds ratio (OR) of the analyzed ECG criteria increased after adding VFATL and BMI to the models. Furthermore, ROC curves analysis exposed better characteristics in detecting LVH of VFATL‐adjusted criteria than BMI‐adjusted and unadjusted criteria.

Conclusions

Adjusting ECG indexes to BMI or VFATL improves the sensitivity of LVH detection. VFATL‐corrected indexes are more sufficiently than BMI‐corrected. After advancements in indexes, both lean and morbidly obese individuals outcomes show a greater prevalence of correct LVH diagnosis.

Medium to Long Term Follow-Up of Treated Hypertensive Mediated Heart Disease

Introduction

Hypertensive mediated heart disease is the consequence of anatomical and functional changes in cardiovascular system. The benefits on left ventricular (LV) diastolic impairment and remodeling of hypertension treatment are well established.

Aim

To evaluate LV structure, systolic and diastolic function of treated hypertensive patients on a medium to long term follow-up.

Methods

Prospectively observational cohort study. Hypertensive patients over 18 years, ultrasound evaluation of LV structure and diastolic and systolic function, follow-up at least once a year. Diastolic function assessed following recommendations of the American Society of Echocardiography and the European Association of Cardiovascular Imaging.

Results

285 patients, mean follow up of 1731 ± 952 days. Sample mean age 56.3 ± 12.5 years, 166 patients (58.3%) were males. Baseline blood pressure 147.8 ± 19/86.8 ± 11 mm Hg, 5 years blood pressure 134.4 ± 15.7/79 ± 9 mm Hg (p < 0.005 SBP and p < 0.01 DBP). Baseline fixed dose combinations 115 patients (40.4%), follow-up 53.1% (p < 0.05). LV remodeling was detected in 88 patients (30.9%) vs. 30.1% at 5 years (p = NS). The frequency of an E/e′ ratio > 14 was reduced from 38 patients (13.3%) to 3.6% (p < 0.001), e′ septal velocity < 7 cm/sec or e′ lateral velocity < 10 cm/sec was reduced from 38.6% (110 patients) to 19.3% (p < 0.001). Baseline normal diastolic function was detected in 85.6% (244 patients) and 94% at the end of the follow-up (p < 0.02).

Conclusions

In this observational cohort followed by a mean of 5 years, the main benefit of hypertension treatment was the prevention or regression of diastolic dysfunction.

Level of Physical Activity, Left Ventricular Mass, Hypertension, and Prognosis

Left ventricular hypertrophy is a strong predictor of prognosis in hypertension. Physical activity is associated with higher left ventricular mass but also reduced risk of cardiovascular outcomes. The aims were to explore whether (1) presence of hypertension modifies the association between physical activity and left ventricular mass; (2) the beneficial association between physical activity and prognostic outcome is modified by left ventricular hypertrophy. Randomly selected number of 3078 persons from the general population underwent echocardiogram. Left ventricular mass was indexed to body surface area. Level of physical activity was self-reported: inactivity, light activity, and moderate/high activity. Blood pressure was measured in rest: normal BP (<140/90 mm Hg) and hypertension (≥140/90 mm Hg or in pharmacological treatment for hypertension). Presence of hypertension modified the association between physical activity and left ventricular mass index significantly (test for interaction: P =0.01): in normal BP, higher levels of physical activity were associated with significantly higher left ventricular mass index ( P <0.001), but this was not present in hypertension ( P =0.90). Level of physical activity was associated with reduction in mortality and cardiovascular outcome independent of the presence of LVH (Persons with LVH: light activity HR, 0.77 [0.52–1.15], moderate/high activity HR, 0.61 [0.38–0.97]; test for interaction between LVH and level of physical activity P =0.71). In conclusion, persons with normal BP had higher left ventricular mass index at increased levels of physical activity, whereas this association was not present among persons with hypertension. Level of physical activity was associated with better prognosis independent of whether left ventricular hypertrophy was present or not.

Differential impact of local and regional aortic stiffness on left ventricular remodeling: a cardiovascular magnetic resonance study

BACKGROUND

Left ventricular (LV) remodeling and aortic stiffness have independent predictive value for all causes and cardiovascular mortality. Because elastic properties of the arterial wall vary along the aortic pathway, we hypothesized that local and regional aortic stiffness could differently impact on LV remodeling.

METHODS AND RESULTS

Regional aortic stiffness was determined from carotid-femoral pulse wave velocity (cfPWV) measured by aplanation tonometry. Aortic arch pulse wave velocity was measured by phase contrast cardiovascular magnetic resonance (CMR). Local stiffness was calculated in the ascending aorta pulse wave velocity (aaPWV) and descending aorta pulse wave velocity using central pulse pressure measurement, cine CMR acquisition, and surface change estimation. CMR LV remodeling was expressed as LV mass to end-diastolic volume ratio.We evaluated 146 study participants (41 ± 15 years) free of overt cardiovascular disease. In stepwise multivariate regression analysis, cfPWV and aaPWV were significantly and independently correlated to mass to end-diastolic volume ratio (partial R = 0.07 and R = 0.10, respectively, all P < 0.005) after adjustment for age, sex, BMI, brachial mean blood pressure, and central pulse pressure. Descending aorta pulse wave velocity was correlated with mass to end-diastolic volume ratio to a lower extent (R = 0.04, P = 0.0115) and aortic arch pulse wave velocity was not independently associated with mass to end-diastolic volume ratio. CfPWV and aaPWV were both independently associated with mass to end-diastolic volume ratio, explaining 5 and 8% of mass to end-diastolic volume ratio variance, respectively.

CONCLUSION

In study participants free of overt cardiovascular disease, stiffness of the ascending aorta representing the local proximal aortic function face to the LV and of the downstream aortic pathway assessed by cfPWV reflecting more advanced alterations of material properties involving the entire aorta, are independent determinants of LV remodeling after adjustment to age, BMI, mean blood pressure, and sex.

[Echocardiographic profile of Congolese hypertensive patients]

OBJECTIVES

To assess echocardiographic aspect of Congolese hypertensive patients, and to identify predictive factors of left ventricular hypertrophy (LVH).

PATIENTS AND METHODS

A transversal study was lead in Brazzaville from January 2011 to December 2013 (36 months). In total, 1125 hypertensive patients under treatment underwent transthoracic echocardiography. The test was carried out either as part of an initial assessment of the hypertension disease or during the development of evocative symptom or complication. Patients' sociodemographic data and echocardiographic parameters were collected and analyzed.

RESULTS

There were 621 males (55.2%) and 504 females (44.8%), mean age 54.7±12 years. The main indication of the test were the hypertension initial evaluation in 792 cases (70.4%), dyspnea in 122 cases (10.8%), investigation of ischemic stroke in 101 cases (9%), cardiac failure and chest pain in respectively 58 and 52 cases. 5.3±4.7 years known duration of hypertension status was associated with overweight/obesity in 829 cases (73.7%), physical inactivity in 669 cases (59.5%), hypertension family history in 540 cases (48%), diabetes mellitus in 122 cases (10.8%), dyslipidemia in 82 cases (7.3%), smoking in 29 cases (2.6%). Echocardiographic test was abnormal in 590 cases (52.4%) and showed hypertrophic cardiomyopathy in 510 cases (45.2%), dilated and hypertrophic cardiomyopathy in 46 cases (4.1%), dilated cardiomyopathy with systolic dysfunction in 31 cases (2.8%), coronary artery disease in 4 cases (0.4%). LVH was concentric in 470 cases (84.6%), eccentric in 70 cases (12.6%), and in 16 cases (3%), it was a concentric left ventricular remodeling. The left ventricular's systolic ejection fraction average was 70.5±9.3%, relaxation disorders in 480 cases (42.6%). Age, male gender, income, known duration of hypertension and treatment were predictive factors of LVH.

CONCLUSIONS

Echocardiographic profile of the Congolese hypertensive is quite various, left ventricular hypertrophy is the most predominant abnormality. Efficient management on the hypertension will lead to reduce its morbidity and mortality.

Acute pulmonary edema in patients with reduced left ventricular ejection fraction is associated with concentric left ventricular geometry

Although acute pulmonary edema (APE) is common in patients with heart failure (HF) with preserved ejection fraction (EF), its pathogenesis in patients with HF with reduced EF (HFrEF) is not completely understood. The purpose of our study was to explore the contributions of left ventricular (LV) geometry to understand the difference between HFrEF patients with or without APE. We studied 122 consecutive acute decompensated HF patients with HFrEF (≤40%). APE was defined as acute-onset dyspnea and radiographic alveolar edema requiring immediate airway intervention. LV geometry was determined from a combination of the LV mass index and relative wall thickness (RWT). Long-term unfavorable outcome events were tracked during a follow-up of a median of 21 months (interquartile range, 10-28 months), during which APE was observed in 29 patients (24%). Compared to those without APE, hospitalized patients with APE had a higher systolic blood pressure, RWT, and LVEF and lower end-diastolic dimension. Among echocardiographic variables, a multivariate logistic regression analysis identified RWT as the only independent determinant of APE (hazard ratio: 2.46, p < 0.001). Those with concentric geometry (n = 25; RWT > 0.42) had a higher incidence of APE relative to those with non-concentric geometry. Furthermore, among patients with APE, mortality was significantly higher among those with concentric geometry (log-rank, p = 0.008). Compared with non-concentric geometry, concentric geometry (increased RWT, not LV mass) was strongly associated with APE onset and a poorer outcome among APE patients. An easily obtained echocardiographic RWT index may facilitate the risk stratification of patients.

Morphologic and Functional Heart Abnormalities Associated to High Modified Tei Index in Hypertensive Patients

INTRODUCTION

LV dysfunction develops early in hypertension, even previously to left ventricular remodeling.

AIMS

To determine the frequency of morphologic and functional heart abnormalities associated to abnormal modified Tei Index in untreated hypertensive (HBP) patients (p) with preserved ejection fraction (pEF).

METHODS

Case-control study. Three groups: (1) HBP without left ventricular hypertrophy (LVH); (2) HBP with LVH; (3) non-HBP controls. Ejection fraction >54 % identified pEF. LVH measured by Devereux method. Systolic and diastolic functions assessed by standard echocardiography and tissue Doppler. 2013 ESH/ESC Hypertension Guidelines normal values were considered. Tei index measured at the lateral and septal LV walls in apical 4-chamber view by tissue Doppler, value >0.40 considered abnormal.

STATISTICAL ANALYSIS

multifactorial ANOVA test adjusted by sex and age, p < 0.05 statistically significant.

RESULTS

The study included 14 controls, 88 HBP p without LVH, and 19 HBP p with LVH. The HBP p sample mean age was 58.7 ± 13.5 years and 52 (44.1 %) were males. Mean Tei Index was 0.35 ± 0.03 in controls; 0.42 ± 0.05 in HBP without LVH; and 0.42 ± 0.06 in HBP with LVH (p < 0.025). Abnormal Tei Index was present in 2p (14.3 %) controls; 64 p (72.7 %) HBP without LVH; and 15 p (78.9 %) HBP with LVH (p < 0.0009). Tissue Doppler's wave was 8.4 ± 0.9 cm/s in controls; 8 ± 1.6 cm/s in HBP without LVH and 7.8 ± 1.1 cm/s in HBP with LVH.

CONCLUSIONS

(1) Left ventricular dysfunction is frequent in HBP p, even without LVH; (2) modified tissue Doppler Tei index is a useful tool for the diagnosis of left ventricular dysfunction.

Functional Organ Damage in Cardiovascular Low Risk Patients with High Central Aortic Pressure

BACKGROUND

The loss of the viscoelastic properties of central arteries independently of blood pressure loads could stimulate the development of left ventricular hypertrophy and dysfunction, renal failure, or cerebral vascular injury.

OBJECTIVE

The aim of the present study is to determine if an elevated systolic aortic pressure is a marker of more frequent target organ damage (TOD) in hypertensive low cardiovascular risk (CVR) patients.

METHODS

Hypertensive non treated consecutive patients (p) assisted at first visit in a specialized center with a CVR according to WHO Americas B area score less than 10 % were included. Left ventricular mass index (LVMI) and tissue Doppler diastolic and systolic function were measured as Lang et al. (J Am Soc Echocardiogr 18:1440-1463, 2005) and Nagueh et al. (J Am Soc Echocardiogr 22:107-133, 2009). Cardiac TOD was considered according to 2013 European Society of Hypertension/European Society of Cardiology. Glomerular filtration rate (GFR) was calculated by MDRD formula, a value <60 ml/min/1.73 m(2) was considered TOD. Systolic aortic pressured (CAoP) was measured by radial tonometry and classified according to criteria proposed by Herbert et al. (Eur Heart J 35:3100-3132, 2014). Continue variables are reported as means with standard deviation and discrete variables as absolute values and percentages. Statistical analysis was performed with Students t test, significant differences were considered with a p value < 0.05 RESULTS: 155 p were included; 23 p (14.8 %) had elevated CAoP while 132 p (85.2 %) had normal CAoP. Sample mean age was 54.1 + 12.9 years; 85 p (54.8 %) were males. Dyslipidemia was detected in 44 p (28.4 %), and 18 p (11.6 %) were smokers. Mean blood pressure was 143.7 + 17.1 mmHg/86.4 + 12.3 mmHg in p with normal (n) CAoP and 140.3 + 12 mmHg/81.9 + 6.8 mmHg in p with CAoP elevated e (p = NS). Mean CAoP in p with normal values was 117.4 + 10.9 mmHg and 116.9 + 10.7 in p with elevated values (p = NS). The average s wave was 7.42 + 1 cm/sec in n CAoP p vs 6.6 + 1 cm/sec in e CAoP p (p < 0.05) while and E/e' ratio >13 was detected in 14.4 % n CAoP p vs 8.7 % e CAoP p (p = NS). Mean GFR was 105.4 + 40.5 ml/min/1.73 m(2) in n CAoP p vs 103.9 + 45.6 ml/min/1.73 m(2) in e CAoP p (p = NS) and GFR <60 ml/min/1.73 m(2) was present in 4.5 % n CAoP p vs 26.1 % e CAoP p (p < 0.0125).

CONCLUSIONS

At the same level of CVR according to WHO Americas B score patients with elevated CAoP had lower longitudinal left ventricular systolic function and renal function was more deteriorated.

Left ventricular mass and progenitor cells in chronic heart failure patients

The aim of the study was to evaluate the association between circulating (CPCs) and endothelial (EPCs) progenitor cells and left ventricular (LV) remodeling in chronic heart failure (HF). 85 HF patients, ranging 29-89 years, 83.5% males, 45.9% ischemic, NYHA functional class II-IV, with a LV ejection fraction ≤40% were studied. LV ejection fraction, LV end-diastolic and end-systolic (LVESV) volumes, LV mass and tricuspid annular plane systolic excursion (TAPSE) were evaluated, and, when indicated, indexed for body surface area (BSA). CPCs and EPCs number was assessed using flow cytometry. CPCs were defined as CD34+, CD133+ and CD34+/CD133+. EPCs, identified through their expression of KDR, were defined as CD34+/KDR+, CD133+/KDR+ and CD34+/CD133+/KDR+. All EPCs were negatively related to LVESV/BSA (r = -0.24, p = 0.02 for all EPC's populations), and to LVmass/BSA (CD34+KDR+; r = -0.30, p = 0.005; CD133+KDR+; r = -0.31, p = 0.004; CD34+CD133+KDR+; r = -0.29, p = 0.007). No differences in EPCs levels in relation to cardiovascular risk factors, medications, etiology, age or gender were observed. CPCs number was higher in women, and lower in ischemic patients. In logistic regression analyses, the low EPCs' number was associated with an increased likelihood of abnormal LVmass/BSA. CPCs proved to be higher and EPCs lower in patients with severely abnormal LVmass/BSA (gr/m(2), ≥122 in women and ≥149 in men). Our results suggest a correlation between LV remodeling and progenitor cells. This is noteworthy considering that it has been suggested that bone marrow-derived EPCs participate in cardiac regeneration and function recovery in the setting of progressive HF.

Relationship between extent and complexity of coronary artery disease and different left ventricular geometric patterns in patients with coronary artery disease and hypertension

OBJECTIVE

The relationship between severity of coronary artery disease (CAD) and left ventricler (LV) hypertrophy in hypertensive patients is well known. However, the association between the extent and complexity of CAD assessed with SYNTAX score (SS) and different LV geometric patterns has not been investigated. We aimed to investigate the association between SYNTAX score and different LV geometric patterns in hypertensive patients.

METHODS

The study had been made in our clinic between January 2013 and August 2013. We studied 251 CAD patients who had hypertension and who underwent coronary angiography (147 males, 104 females; mean age 61.61±9.9 years). Coronary angiography was performed based on clinical indications. SS was determined in all patients. Echocardiographic examination was performed in all subjects. Four different geometric patterns were determined in patients according to LV mass index (LVMI) and relative wall thickness (RWT) (Groups: NG- normal geometry, CR- concentric remodeling, EH- eccentric hypertrophy, and CH- concentric hypertrophy). Biochemical markers were measured in all participants.

RESULTS

The highest SS values were observed in the CH group compared with the NG, CR, and EH groups (p<0.05 for all). Also, the SS values of the EH group were higher than in the NG and CR groups (p<0.05 for all). Multivariate linear regression analysis showed that SS was independently associated with LV geometry (β=0.316, p=0.001), as well as age (β=0.163, p=0.007) and diabetes (β=-0.134, p=0.022).

CONCLUSION

SYNTAX score is independently related with LV geometry in hypertensive patients. This result shows that LV remodeling is parallel to the increase in the extent and complexity of CAD in our study patients.

Hypertension in African Americans with heart failure: progression from hypertrophy to dilatation; perhaps not

AIM

Concentric hypertrophy is thought to transition to left ventricular (LV) dilatation and systolic failure in the presence of long standing hypertension (HTN). Whether or not this transition routinely occurs in humans is unknown.

METHODS

We consecutively enrolled African American patients hospitalized for acute decompensated volume overload heart failure (HF) in this retrospective study. All patients had a history of HTN and absence of obstructive coronary disease. Patients were divided into those with normal left ventricular ejection fraction (LVEF) and reduced LVEF. LV dimensions were measured according to standard ASE recommendations. LV mass was calculated using the ASE formula with Devereux correction.

RESULTS

Patients with normal LVEF HF were significantly older, female and had a longer duration of HTN with higher systolic blood pressure on admission. LV wall thickness was similarly elevated in both groups. LV mass was elevated in both groups however was significantly greater in the reduced LVEF HF group compared to the normal LVEF HF group. Furthermore, gender was an independent predictor for LV wall thickness in normal LVEF HF group.

CONCLUSION

In African American patients with HF our study questions the paradigm that concentric hypertrophy transitions to LV dilatation and systolic failure in the presence of HTN. Genetics and gender likely play a role in an individual's response to long standing hypertension.

Effects of a low-volume aerobic-type interval exercise on VO2max and cardiac mass

PURPOSE

The aim of this study was to compare the effects of time-efficient, low-volume interval exercises on cardiorespiratory capacity and left ventricular (LV) mass with traditional continuous exercise in sedentary adults.

METHODS

Forty-two healthy but sedentary male subjects (age 26.5 ± 6.2 yr) participated in an 8-wk, five times per week, supervised exercise intervention. They were randomly assigned to one of three exercise protocols: sprint interval training (SIT, 5 min, 100 kcal), high-intensity interval aerobic training (HIAT, 13 min, 180 kcal), and continuous aerobic training (CAT, 40 min, 360 kcal). Cardiorespiratory capacity (V˙O2max) and LV mass (3T-MRI) were measured preintervention and postintervention.

RESULTS

We observed significant (P < 0.01) increases in V˙O2max in all three groups, and the effect of the HIAT was the greatest of the three (SIT, 16.7% ± 11.6%; HIAT, 22.5% ± 12.2%; CAT, 10.0% ± 8.9%; P = 0.01). There were significant changes in LV mass, stroke volume (SV), and resting HR in both the SIT (LV mass, 6.5% ± 8.3%; SV, 5.3% ± 8.3%; HR, -7.3% ± 11.1%; all P < 0.05) and HIAT (LV mass, 8.0% ± 8.3%; SV, 12.1% ± 9.8%; HR, -12.7% ± 12.2%; all P < 0.01) but not in the CAT (LV mass, 2.5% ± 10.1%; SV, 3.6% ± 6.6%; HR, -2.2% ± 13.3%; all P > 0.05).

CONCLUSIONS

Our study revealed that V˙O2max improvement with the HIAT was greater than with the CAT despite the HIAT being performed with a far lower volume and in far less time than the CAT. This suggests that the HIAT has potential as a time-efficient training mode to improve V˙O2max in sedentary adults.

Meta-analysis of accuracy of left ventricular mass measurement by three-dimensional echocardiography

Left ventricular (LV) hypertrophy is a fundamental prognostic factor in a variety of cardiac diseases. Three-dimensional echocardiography (3DE) has achieved better estimation of LV mass than 2-dimensional echocardiography. However, significant underestimation has often been reported, and no previous study has synthesized these data. The aim of this meta-analysis was to investigate if there has been improvement in the accuracy in LV mass measurement by 3DE over time. Studies comparing LV mass between 3DE and magnetic resonance imaging were eligible. A cumulative meta-analysis was performed to investigate improvement in accuracy, followed by subgroup and meta-regression analysis to reveal factors affecting the bias. A total of 25 studies including 671 comparisons were analyzed. Studies published in or before 2004 showed high heterogeneity (I(2) = 69%) and significant underestimation of LV mass by 3DE (-5.7 g, 95% confidence interval -11.3 to -0.2, p = 0.04). Studies published from 2005 to 2007 were still heterogenous (I(2) = 60%) but showed less systematic bias (-0.5 g, 95% confidence interval -2.5 to 1.5, p = 0.63). In contrast, studies published in or after 2008 were highly homogenous (I(2) = 3%) and showed excellent accuracy (-0.1 g, 95% confidence interval -2.2 to 1.9, p = 0.90). Investigation of factors affecting the bias revealed that evaluation of cardiac patients compared to healthy volunteers led to larger bias (p <0.05). In conclusion, this meta-analysis elucidates the underestimation of LV mass by 3DE, its improvement over the past decade, and factors affecting the bias. These data provide a more detailed basis for improving the accuracy of 3DE, an indispensable step toward further clinical application.

Left ventricular torsional mechanics in uncomplicated pregnancy

BACKGROUND

Alterations in left ventricular (LV) twist (torsion) and untwist have been described for a variety of physiologic and pathologic conditions. Little information is available regarding changes in these parameters during normal pregnancy.

HYPOTHESIS

Pregnancy is associated with significant changes in LV torsional mechanics.

METHODS

Left ventricular twist and untwist was measured in 32 pregnant females (mean gestation 199 ± 48 d) and 23 nonpregnant controls using speckle-tracking echocardiography.

RESULTS

Left ventricular ejection fraction (68 ± 5% vs 66 ± 5%) was similar between the groups (P not significant). There was a significant increase in peak LV twist from nonpregnant controls (9.4 ± 3.7 degrees) to second-trimester (12.0 ± 4.2 degrees) and third-trimester subjects (12.6 ± 5.9 degrees, all P<0.05). Peak LV twist velocity was also increased in second- and third-trimester groups compared with controls (94 ± 24 degrees/sec and 93 ± 30 vs 64 ± 21 degrees/sec, respectively, both P<0.05). Both peak untwist velocity and time to peak untwist velocity were not significantly different between groups (P not significant). Multiple regression analysis indicate that only systolic blood pressure (r = 0.394, P = 0.005) was an independent predictor for increased LV torsion.

CONCLUSIONS

There are significant changes in LV torsional indices during the course of pregnancy, whereas untwist parameters remain unchanged. Blood pressure is independently associated with increased torsion during pregnancy.

Left ventricle relative wall thickness and plasma leptin levels: baseline relationships and effects of 4 months of walking training in healthy overweight postmenopausal women

OBJECTIVE

Whether leptin has positive or negative influences on cardiac structure and function in healthy sedentary overweight postmenopausal women is unknown. We investigated the role of leptin in cardiac health and whether aerobic fitness enhancement influences any relationships revealed between leptin and echocardiographic measurements.

METHODS

Thirty-nine sedentary postmenopausal women were enrolled after an initial screening. The women underwent blood sampling for hormone levels, anthropometric and echocardiographic measurements, dietary habits investigation, and fitness testing, both before and after 4 months of walking training.

RESULTS

After the intervention, the women who had an adherence to training of 75% or higher showed significantly reduced percentage fat mass (P = 0.006) and plasma leptin levels (P < 0.001), whereas their maximum oxygen consumption increased significantly (P < 0.001). The women showed a significant reduction in left ventricle relative wall thickness (P = 0.039) and significant increases in both left ventricular end-diastolic diameter (P = 0.040) and left ventricular mass index (P = 0.043). At baseline, a negative correlation was seen between plasma leptin levels and left ventricle relative wall thickness (r = -0.553; P = 0.009). Further negative correlations were seen for the changes in left ventricle relative wall thickness with leptin levels (r = -0.456; P = 0.038) and with tricipital skinfold (r = -0.436; P = 0.05).

CONCLUSIONS

In healthy overweight sedentary postmenopausal women with low fitness level, high plasma leptin levels seem to have a protective role against left ventricle relative wall thickness hypertrophy and to participate in its remodeling after 4 months of aerobic training.

Ghrelin PYY 3-36 serum changes in left ventricular hypertrophic, insulin-resistant, hypertensive obese patients

AIM

Hypertension is a major health problem and is usually associated with common conditions such as obesity, which contribute to clinical cardiac dysfunction. The role of energy homeostasis hormones such as ghrelin and PYY 3-36 in cardiovascular function remains incompletely understood. Therefore, the aim of our study was to explore the potential differences in concentrations of ghrelin forms and PYY 3-36 circulating in obese patients with grade 1 and grade 2 hypertension, with higher and lower BMI and without and with insulin resistance as well as to determine whether these hormones may be associated with left ventricular hypertrophy.

METHODS

A total of 142 adult subjects were studied in three subgroups: lean (BMI < 25 kg/m(2)) normotensive subjects and obese subjects (BMI 30.0-34.9 kg/m(2)), and obese subjects (BMI 35.0-39.9 kg/m(2)) under hypertensive treatment for at least 9 years. Fasting blood glucose, insulin, high-sensitivity C-reactive protein (hs-CRP), lipid profile, urinic acid, acylated ghrelin (A-Ghr), total ghrelin (T-Ghr), and PYY 3-36 were measured. Insulin resistance was determined by the homeostasis model assessment of insulin resistance (HOMA-IR). We also echocardiographically assessed left ventricular mass (LVM) index (LVMI = LVM/height(2.7)). We evaluated the association between plasma T-Ghr, A-Ghr, PYY 3-36 levels with LVMI and other measured factors using univariate and multivariate analysis.

RESULTS

There were significant differences between BMI, waist circumference (WC), LVMI, hs-CRP and A-Ghr/nonacylated ghrelin (NA-Ghr) ratio (in the two obese subgroups. There was no significant difference between T-Ghr, A-Ghr and PYY 3-36 levels between obese subgroups. T-Ghr and PYY 3-36 were significantly lower in obese patients than in the control group, whereas A-Ghr levels did not differ between obese and controls. A-Ghr/NA-Ghr ratio was significantly higher in patients with second-degree hypertension and BMI 35.0-39.9 kg/m(2) than in patients with first-degree hypertension and BMI 30.0-34.9 kg/m(2). There were negative associations between T-Ghr, NA-Ghr or PYY 3-36 and LVMI (r = -0.49, p = 0.0001; r = -0.47, p = 0.0001; or r = -0.18, p = 0.029, respectively) and positive association between A-Ghr/NA-Ghr ratio and LVMI (r = 0.3, p = 0.0003). T-Ghr and NA-Ghr, were associated negatively with fasting insulin (r = -0.31, p = 0.0025; and r = -0.36, p = 0.001, repectively), while A-Ghr/NA-Ghr ratio was positively associated with BMI and fasting insulin (r = 0.23, p = 0.041; r = 0.3, p = 0.0045, respectively). T-Ghr, A-Ghr, and NAGhr were also inversely related to HOMA-IR indices in obese patients (r = -0.43, p = 0.001; r = -0.32, p = 0.0359; r = -0.35, p = 0.001, respectively). In insulin-resistant obese subjects T-Ghr and NA-Ghr correlated negatively with HOMA-IR (r = -0.34, p = 0.0015; r = -0.28, p = 0.0116, respectively). LVMI was associated negatively with T-Ghr, NA-Ghr and PYY 3-36 (r = -0.49, p = 0.0001; r = -0.47, p = 0.0001; r = -0.18, p = 0.029, respectively). In addition, LVMI was positively associated with A-Ghr/NA-Ghr ratio (r = 0.30, p = 0.0003).

CONCLUSION

Plasma ghrelin forms and PYY 3-36 levels are associated with LVMI. These associations indicate a possible interaction between gut peptides and the cardiovascular system in hypertension and obesity.

Comparison of methods to measure heart size using noncontrast-enhanced computed tomography: correlation with left ventricular mass

OBJECTIVE

Left ventricular (LV) mass is a useful independent predictor of cardiovascular events. We sought to develop a new correlate of LV mass using noncontrast-enhanced cardiac computed tomography (NCE-CCT).

METHODS

We assessed 22 different ventricular measurements made with NCE-CCT in 60 participants in the Multi-Ethnic Study of Atherosclerosis. The primary outcome was the correlation between the NCE-CCT measurements and magnetic resonance imaging (MRI)-derived LV mass.

RESULTS

Correlation coefficients (r) for the 22 NCE-CCT techniques in comparison to MRI-derived LV mass ranged from 0.12 to 0.80, with 14 of the 22 techniques having r > 0.7. The highest correlation was achieved using the modified Simpson Rule method to determine the biventricular volume (r = 0.80; P < 0.001). Interrater reliability was good, with intraclass correlation coefficients of 0.84 to 0.90 for the best (r > 0.75) NCE-CCT methods.

CONCLUSIONS

Noncontrast-enhanced cardiac computed tomography measurements of both biventricular volume and LV volume correlated well with MRI-derived LV mass in a population free of clinical cardiovascular disease.

Effect of Geometric Remodeling on Left Ventricular Longitudinal Contractile Reserve in Patients with Hypertension

Left ventricular hypertrophy (LVH) is associated with a reduction of subendocardial coronary flow reserve, which may be associated with abnormal myocardial longitudinal function during exercise. To test this hypothesis, 182 hypertensive patients underwent multistage supine bicycle exercise testing. Patients were classified as follows: patients with normal geometry (group 1, n = 116), concentric remodeling (group 2, n = 31), or LVH (group 3, n = 31). The results showed that the ratio of E/E', an index of left ventricular (LV) filling pressure, was significantly elevated in the LVH group at rest and during exercise. At rest, the mitral annular systolic velocity (S') was similar between the three groups at rest, whereas S' during exercise was significantly lower in the LVH group. The magnitude of change in S' during exercise was also significantly lower in the LVH group. Multiple linear regression analysis showed that peak double product (beta = 0.208, P = .006) and LV mass index (beta = -0.158, P = .028) were independently associated with LV longitudinal contractile reserve. Also, multiple linear regression analysis showed that changes in S' from baseline to peak were independently associated with exercise duration (beta = 0.123, P = .041) when controlled for age, male gender, baseline E', peak systolic blood pressure, and LV mass index. The results from this study demonstrate that LVH was significantly associated with abnormal LV longitudinal contractile reserve in hypertensive patients.

Association of depressed cardiac gp130-mediated antiapoptotic pathways with stimulated cardiomyocyte apoptosis in hypertensive patients with heart failure

OBJECTIVE

To investigate whether the glycoprotein (gp130)-mediated survival pathway, which protects cardiomyocytes from apoptosis, is depressed in left ventricular hypertrophy hypertensive patients with chronic heart failure.

METHODS

Transvenous endomyocardial biopsies were obtained in 52 hypertensive patients with left ventricular hypertrophy: 28 without heart failure and 24 with heart failure. gp130 and gp130-dependent antiapoptotic pathways p42/44 mitogen-activated protein kinase (MAPK) and phosphatidylinositol-3 kinase (PI3K)/protein kinase B (Akt) as well as gp130 agonist cardiotrophin-1 were analyzed by reverse transcriptase-polymerase chain reaction and western blot. Apoptosis was assessed by DNA end-labeling (TUNEL), caspase-3 immunostaining and caspase substrate poly(ADP-ribose) polymerase cleavage.

RESULTS

gp130 protein expression (P < 0.05) and p42/44 MAPK and PI3K/Akt activation (P < 0.01) were decreased in heart-failure hypertensive patients compared with nonheart-failure hypertensive individuals. No changes in gp130 mRNA expression were found between the two groups. Cardiotrophin-1 was increased (P < 0.05) at both the mRNA and protein levels in heart-failure hypertensive individuals compared with nonheart-failure hypertensive individuals. Cardiomyocyte apoptosis was increased (P < 0.01) in heart-failure hypertensive individuals compared with nonheart-failure hypertensive individuals. Inverse correlations (P < 0.01) occurred between cardiomyocyte apoptosis and p42/44 MAPK and PI3K/Akt activation in all hypertensive patients. Cardiotrophin-1 correlated inversely (r = -0.554, P < 0.05) with gp130 in all hypertensive individuals. In cultured HL-1 cardiomyocytes, cardiotrophin-1 decreased (P < 0.05) the gp130:phosphorylated gp130 (at Ser782) ratio and increased (P < 0.05) gp130ubiquitination.

CONCLUSIONS

An association exists between depression of the gp130 cytoprotective pathway and stimulation of cardiomyocyte apoptosis in hypertensive patients that develop heart failure. Whether the excess of cardiotrophin-1 induces ligand-induced receptor down-regulation in these patients requires further study.

Ventricular Structure and Function in Hypertensive Participants With Heart Failure and a Normal Ejection Fraction

OBJECTIVES

The purpose of this study was to evaluate left ventricular (LV) size and structure in elderly subjects with hypertension (HTN) and heart failure who have a normal ejection fraction (HFNEF) in a large population-based sample.

BACKGROUND

The pathophysiology of HFNEF is incompletely understood but is generally attributed to LV diastolic dysfunction with normal or reduced LV diastolic chamber size despite greater than normal filling pressures.

METHODS

In the Cardiovascular Health Study (n = 5,888), demographic and clinical characteristics and ventricular structure and function were compared in healthy normal subjects (healthy; n = 499), subjects with HTN but not heart failure (HTN; n = 2,184), and subjects with HTN and HFNEF (HFNEF; n = 167).

RESULTS

Subjects with HFNEF were older, more obese, and more often African American than healthy and HTN subjects and had a higher prevalence of diabetes, coronary heart disease, and anemia than HTN subjects. Serum creatinine and cystatin-C were increased in HFNEF subjects. Average LV diastolic dimension was significantly increased in HFNEF subjects (5.2 +/- 0.8 cm) compared with healthy (4.8 +/- 0.6 cm) and HTN (4.9 +/- 0.6 cm) subjects. As a result, average calculated stroke volume (89 +/- 25 ml vs. 78 +/- 20 ml and 80 +/- 20 ml) and cardiac output (6.0 +/- 2.0 l/min vs. 4.8 +/- 1.3 l/min and 5.1 +/- 1.4 l/min) were increased in HFNEF compared with healthy and HTN subjects, respectively.

CONCLUSIONS

As a group, HFNEF subjects have increased LV diastolic diameter and increased calculated stroke volume. They also have increased prevalence of multiple comorbidities, including anemia, renal dysfunction, and obesity, that can cause volume overload. These data suggest that extracardiac factors, via volume overload, may contribute to the pathophysiology of HFNEF in the elderly.

Regression of left ventricular hypertrophy with moexipril, an angiotensin-converting enzyme inhibitor, in hypertensive patients

Left ventricular hypertrophy (LVH) is a common complication of essential hypertension and an independent risk factor for the development of cardiovascular disease. Therefore, antihypertensive treatment should decrease blood pressure (BP) and reverse LVH. However, antihypertensive drugs have been shown to have different effects on LVH despite similar effects on BP reduction. Although lowering BP produces a beneficial effect on LVH per se, meta-analyses of clinical trials have indicated that angiotensin-converting enzyme (ACE) inhibitors decrease left ventricular mass (LVM) to a greater extent than do some other antihypertensives. The aim of this study was to evaluate the effect of a 24-week treatment with the ACE inhibitor moexipril (15 mg once daily) on the regression of LVH in hypertensive patients. This was a multicenter, international, single-blind, single-group, nonrandomized study. After a wash-out placebo period of 2 weeks, 15 mg moexipril once daily was administered for 24 weeks followed by a 2-week follow-up placebo period. Subjects with mild to moderate essential hypertension were screened; those with LVH [defined as an LVM indexed for body surface area (LVMIs) >111 g/m in men and LVMIs >106 g/m in women] were eligible to participate in this study. Echocardiograms were recorded on videotape and sent to a centralized laboratory for reading by 2 independent experts blinded for treatment, center, and visit; the mean values of these readings were calculated and used for analysis. Valid echocardiographic data were obtained from 72 patients (50 males, 22 females) with a mean age of 49 +/- 11 years. Analysis showed significant decrease of LVMIs (121 +/- 20 versus 103 +/- 17 g/m; P < 0.001) and BP (152 +/- 12/96 +/- 9 versus 140 +/- 13/86 +/- 9 mm Hg; P < 0.001) with moexipril. For patients who met LVMI inclusion criteria after centralized, blinded readings, the decrease from baseline in LVMIs was 23.4 g/m. The decrease in LVMIs was independent from the regression to the mean phenomenon as observed from the follow-up placebo period. Moexipril 15 mg once daily administered for 24 weeks resulted in a significant reversal of LVH in patients with essential hypertension. The result compares favorably with results previously obtained in trials of similar duration with other ACE inhibitors.

Fast Measurement of Left Ventricular Mass With Real-Time Three-Dimensional Echocardiography

BACKGROUND

Left ventricular (LV) mass is an important predictor of morbidity and mortality, especially in patients with systemic hypertension. However, the accuracy of 2D echocardiographic LV mass measurements is limited because acquiring anatomically correct apical views is often difficult. We tested the hypothesis that LV mass could be measured more accurately from real-time 3D (RT3D) data sets, which allow offline selection of nonforeshortened apical views, by comparing 2D and RT3D measurements against cardiac MR (CMR) measurements.

METHODS AND RESULTS

Echocardiographic imaging was performed (Philips 7500) in 21 patients referred for CMR imaging (1.5 T, GE). Apical 2- and 4-chamber views and RT3D data sets were acquired and analyzed by 2 independent observers. The RT3D data sets were used to select nonforeshortened apical 2- and 4-chamber views (3DQ-QLAB, Philips). In both 2D and RT3D images, LV long axis was measured; endocardial and epicardial boundaries were traced, and mass was calculated by use of the biplane method of disks. CMR LV mass values were obtained through standard techniques (MASS Analysis, GE). The RT3D data resulted in significantly larger LV long-axis dimensions and measurements of LV mass that correlated with CMR better (r=0.90) than 2D (r=0.79). The 2D technique underestimated LV mass (bias, 39%), whereas RT3D measurements showed only minimal bias (3%). The 95% limits of agreement were significantly wider for 2D (52%) than RT3D (28%). Additionally, the RT3D technique reduced the interobserver variability (37% to 7%) and intraobserver variability (19% to 8%).

CONCLUSIONS

RT3D imaging provides the basis for accurate and reliable measurement of LV mass.

Echocardiographic Assessment of Cardiovascular Hemodynamics in Normal Pregnancy

OBJECTIVE

The factors affecting cardiac output in normal pregnancy remain controversial. This study prospectively evaluates maternal central hemodynamics and cardiac structure and function by echocardiography, together with maternal stature correction and correlation of these variables in healthy pregnant women in the latter half of pregnancy.

METHODS

One hundred sixty echocardiographic studies were performed in 35 healthy pregnant women for longitudinal evaluation from early second trimester until term and 6-12 weeks postpartum.

RESULTS

Cardiac output increased significantly at the early to mid third trimester and was maintained until term. It increased predominantly in the latter half of pregnancy, and peak cardiac output of 46-51% occurred from a 15% increase in heart rate and 24% increase in stroke volume. Maternal cardiac output measured in the early third trimester showed a good correlation with maternal body surface area (r = 0.72; P <.001) and fetal birth weight (r = 0.52; P =.008). Left ventricular systolic function was preserved until term.

CONCLUSION

Maternal cardiac output peaks in the early to mid third trimester and is maintained until term. Significant correlations were observed among maternal cardiac output, maternal body surface area, and fetal birth weight.

Electrocardiographic assessment of left ventricular hypertrophy with time–voltage QRS and QRST-wave areas

The sum of time-voltage QRS areas in the 12-lead electrocardiogram (ECG) has outperformed other 12-lead ECG indices for detection of left ventricular hypertrophy (LVH). We assessed indices of time-voltage QRS and T-wave (QRST) areas from body surface potential mapping (BSPM) for detection of and quantitation of the degree of LVH. We studied 42 patients with echocardiographic LVH (LVH group) and 11 healthy controls (controls). QRST area sums were calculated from 123-lead BSPM and from the 12-lead ECG for comparison. Leadwise discriminant indices and correlation coefficients were used to identify optimal recording locations for QRST area-based LVH assessment. BSPM QRS area sum was greater in the LVH group than in controls (3752 +/- 1259 vs 2278 +/- 627 microV s, respectively; P<0.001) and at 91% specificity showed 74% sensitivity for LVH detection. The 12-lead QRS area sum performed similarly. Taking T-wave areas into account did not improve the results. QRS area sum from two most informative leads (located in the upper and lower right precordium) also separated the LVH group from controls (61.1 +/- 23.5 vs 27.8 +/- 6.5 microV s, respectively; P<0.00001). This 2-lead QRS area sum showed 90% sensitivity with 100% specificity for LVH detection and maintained high correlation to indexed left ventricular mass (r=0.732; P<0.001). In conclusion, the BSPM QRS area sum compared to 12-lead QRS area sum does not substantially improve LVH assessment. The 2-lead QRS area sum may improve ECG QRS area-based LVH assessment.

Cardiovascular reactivity and left ventricular mass: An integrative review

Left ventricular hypertrophy has been shown to be an independent predictor of risk for cardiovascular morbidity and mortality. Behavioral scientists have focused on how hemodynamic factors influenced by psychosocial stress may be associated with left ventricular mass (LVM). We reviewed existing studies examining stress-related cardiovascular reactivity (CVR) and LVM, with a goal of examining the moderating role of population (age and hypertensive status) and methodological factors (task type, sample size, and study design) explaining the observed results. Twenty-one studies met the criteria for this review. Results showed only a modestly consistent relationship between CVR and LVM. Forty-three percent of the studies reported 1 or more significant results linking systolic blood pressure reactivity with LVM, and 14% of the studies showed that diastolic blood pressure reactivity was significantly related to LVM. Hypertensive status, task type, and sample size did not play a major role in moderating the relationship between LVM and CVR. A somewhat larger percentage of positive results was shown in prospective and adult studies. The association between CVR and LVM may be real, although the effect size is modest, and we discuss methodological strategies for enhancing statistical power in future investigations. Additional sampling factors (e.g., race, gender) may also impact this relationship. Finally, greater attention is warranted to the role of the psychosocial environment, as this may interact with reactivity to influence LVM.

Comparison of m-mode echocardiographic left ventricular mass measured using digital and strip chart readings: the Atherosclerosis Risk in Communities (ARIC) study

BACKGROUND

Epidemiological and clinical studies frequently use echocardiography to measure LV wall thicknesses and chamber dimension for estimating quantitative measures of LV mass. While echocardiographic M-mode LV images have traditionally been measured using hand-held calipers and strip-chart paper tracings, digitized M-mode LV image measurements made directly on the computer screen using electronic calipers have become standard practice. We sought to determine if systematic differences in LV mass occur between the two methods by comparing LV mass measured from simultaneous M-mode strip chart recordings and digitized recordings.

METHODS

The Atherosclerosis Risk in Communities study applied the latter method. To determine if systematic differences in LV mass occur between the two methods, LV mass was measured from simultaneous M-mode strip chart recordings and digitized recordings.

RESULTS

We found no difference in LV mass (p > .25) and a strong correlation in LV mass between the two methods (r = 0.97). Neither age, sex, nor hypertension status affected the correlation of LV mass between the two methods.

CONCLUSIONS

We conclude that digital estimates of LV mass provide unbiased estimates comparable to the strip-chart method.

High prevalence of target organ damage in young, African American inner-city men with hypertension

Young, urban, African American men are at particularly high risk of hypertension and its cardiovascular complications. Left ventricular hypertrophy and renal dysfunction are manifestations of target organ damage from hypertension that predict adverse cardiovascular events. The subjects of this study were 309 African American men, age 18-54 years, with hypertension, residing in inner-city Baltimore. Echocardiograms, electrocardiograms, serum creatinine, and the urinary albumin-creatinine ratio were obtained to evaluate hypertensive target organ damage. Fifty-three percent of the men reported use of antihypertensive medications, of whom 80% were on monotherapy. Calcium channel blockers were used most frequently. The mean echocardiographic left ventricular mass was 211+/-68 g, with a prevalence of echocardiographic left ventricular hypertrophy of 30%. There were 14 men (5%) with extremely high left ventricular mass, >350 grams. Left ventricular systolic dysfunction was seen in 9% of the men with uncontrolled hypertension, and none of the men with controlled hypertension (p=0.02). Renal dysfunction was found in 12% of the subjects, and microalbuminuria or gross proteinuria in 34%. The authors conclude that there is a high prevalence of cardiac and renal abnormalities in inner-city African American men with hypertension, especially in men on antihypertensive therapy with uncontrolled hypertension. It is imperative that cost-effective medications and culturally acceptable health care delivery programs be developed, tested, and integrated into health systems, with strategies specifically relevant to this high-risk population, to decrease the largely preventable morbidity and mortality associated with hypertension.

Magnetocardiographic indices of left ventricular hypertrophy

OBJECTIVE

We tested the hypothesis that multichannel magnetocardiographic (MCG) mapping can detect and quantify the degree of left ventricular hypertrophy (LVH).

DESIGN

A cross-sectional study.

SETTING

Helsinki University Central Hospital, a tertiary referral center.

PARTICIPANTS

Forty-two patients with pressure overload induced LVH by gender-specific echocardiographic criteria (LVH group), and 12 healthy middle-aged controls.

MAIN OUTCOME MEASURES

MCG QRS-T area integrals and QRS-T angle in magnetic field maps in relation to echocardiographic LVH as well as left ventricular (LV) mass and structure. Conventional 12-lead electrocardiographic (ECG) LVH indices (Sokolow-Lyon voltage, Cornell voltage, Cornell voltage duration product) were assessed for comparison.

RESULTS

MCG QRS- and T-wave integrals provided complementary information of echocardiographic LV mass. Their combination, the QRS-T integral, and the QRS-T angle were increased in patients with LVH and, in those patients, correlated significantly with LV mass indexed to body surface area (r = 0.455;P = 0.002 and r= 0.379; P= 0.013, respectively). A QRS-T integral 16000 fT.s had identical sensitivity of 62% at 92% specificity as the gender-adjusted Cornell voltage duration product of 240 micro V.s for the detection of LVH.

CONCLUSIONS

The MCG method can detect patients with LVH and also quantify the degree of LVH in patients with increased LV mass.

Estimation of myocardial cell damage on the basis of mean electrocardiographic voltage and anatomical left ventricular mass

Left ventricular mass (LVM) as assessed by magnetic resonance imaging (MRI, LVM(MRI)) and electrocardiographic (ECG) voltage reflect different pathological features. We hypothesized that ECG voltage is related to the electrical potential of cardiac muscle cells (electrical LVM) and to anatomical LVM as evaluated by MRI, and that the divergence between electrical LVM and anatomical LVM reflects the degree of myocardial damage. Because adipose tissue has high electrical resistance, we previously found a very strong correlation between body-fat-corrected mean ECG voltage (Vfm) and LVM as estimated by echocardiography in patients with essential hypertension. In this study we compared LVM(MRI), Vfm, the ratio of Vfm x 10(2)/LVM(MRI), and the results of 99mTc tetrofosmin scintigraphy in patients with and without myocardial infarction (MI). We studied 33 patients without Ml and 26 patients with Ml. Vfm significantly correlated with LVM(MRI) in patients without MI (r=0.71, p<0.01). The ratio of Vfm x 10(2)/LVM(MRI) apparently reflected the relation between electrical LVM and anatomical LVM. Vfm x 10(2)/LVM(MRI) in patients with MI was smaller than that in patients without MI (0.98+/-0.28 vs. 1.42+/-0.29, p<0.01). Vfm x 10(2)/LVM(MRI) decreased as 99mTc score increased (r=-0.66, p<0.01). Our results indicate that Vfm is a useful index of electrical LVM and that Vfm x 10(2)LVM(MRI) reflects the electrical potential of the viable myocardium in total anatomical LVM.

Measurement of left ventricular dimensions and function in patients with dilated cardiomyopathy

Studies on medical therapy in heart failure are focused on changes of left ventricular (LV) dimensions and function. These changes may be small, requiring a large study group. We measured LV parameters (LV volumes, LV ejection fraction (LV-EF), and left ventricular mass (LVM)) with two-dimensional echocardiography (2D-echo) and magnetic resonance imaging (MRI) in 50 patients. Based on the difference between the measurements, we determined the variance of the results and calculated the sample sizes needed to detect changes of baseline values. For the calculated and measured parameters we found significant differences between the two techniques: LV-EF and LVM were higher in 2D-echo, and LV dimensions were comparable. The sample size to detect relevant changes from baseline with MRI was significantly (P < 0.01) smaller than in 2D-echo. We conclude that MRI is superior in clinical studies on left ventricular dimensional and functional changes, since measurements are more reproducible and the required sample size is substantially smaller, thereby reducing costs.

Left ventricular mass and atrial volume determined by cine magnetic resonance imaging in essential hypertension

To evaluate the relationship between left atrial volume determined by cine magnetic resonance imaging and progression of left ventricular hypertrophy (LVH), left atrial volume and echocardiographic left ventricular mass (LVM) were measured in 30 hypertensive patients (15 without LVH and 15 with LVH) and 10 normotensive control subjects. We also evaluated the effects of antihypertensive therapy on the cardiac chamber volumes and LVM in hypertensive patients. The cardiac chamber volumes and LVM were indexed by body surface area. Although there were no significant differences in left ventricular chamber volumes among the three groups, both maximum and minimum left atrial volume indexes, and the LVM index were greater in hypertensive patients with LVH than in the other two groups. The LVM index was correlated with maximum left atrial volume index (r = 0.74, P < .0001), and minimum left atrial volume index (r = 0.76, P < .0001), respectively. Furthermore, in multivariate models, the LVM index was significantly correlated with maximum left atrial volume index. In hypertensive patients with LVH, both maximum and minimum left atrial volume indexes, and the LVM index significantly reduced after treatment. The percent of changes in maximum left atrial volume index after treatment was significantly correlated with the percent of changes in LVM index after treatment. In conclusion, our data indicate that LVH is an independent determinant of left atrial enlargement, and both LVH and left atrial enlargement may be reversed by some effective therapeutic interventions.

Serial change in echocardiographic parameters and cardiac failure in end-stage renal disease

Echocardiographic abnormalities are the rule in patients starting dialysis therapy and are associated with the development of cardiac failure and death. It is unknown, however, whether regression of these abnormalities is associated with an improvement in prognosis. As part of a prospective cohort study with mean follow-up of 41 mo, 227 patients had echocardiography at inception and after 1 yr of dialysis therapy. Improvements in left ventricular (LV) mass index, volume index, and fractional shortening were seen in 48, 48, and 46%, respectively. Ninety patients had developed cardiac failure by 1 yr of dialysis therapy. Twenty-six percent of the remaining 137 patients subsequently developed new-onset cardiac failure. The mean changes in LV mass index were 17 g/m(2) in those who subsequently developed cardiac failure compared with 0 g/m(2) among those who did not (P = 0.05). The corresponding values were -8 versus 0% for fractional shortening (P < 0.0001). The associations between serial change in both LV mass index and fractional shortening and subsequent cardiac failure persisted after adjusting for baseline age, diabetes, ischemic heart disease, and the corresponding baseline echocardiographic parameter. Regression of LV abnormalities is associated with an improved cardiac outcome in dialysis patients. Serial echocardiography adds prognostic information to one performed at baseline.

Effects of L-carnitine supplementation on cardiac morbidity in hemodialyzed patients

Cardiac diseases are well known among patients on maintenance hemodialysis (HD), and carnitine deficiency may be an important factor in cardiac morbidity. We studied the effects of low-dose L-carnitine treatment (500 mg/day) on chest symptoms (dyspnea on exertion, chest pain, palpitation), cardiac function, and left ventricular (LV) mass in 9 HD patients with reduced ejection fraction (EF). After 6 months of L-carnitine treatment, most patients had at least some improvement in chest symptoms, while LVEF was increased and LV mass was decreased. Carnitine fractions increased and reached plateaus at 2-3 times the baseline levels. These results suggest that prolonged low-dose L-carnitine treatment can improve the cardiac morbidity by restoring decreased carnitine tissue levels and impaired oxidation of FFA.