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Comparison of the effects of isradipine and lisinopril on left ventricular structure and function in essential hypertension.

The effects on cardiac structure and function of antihypertensive regimens with different effects on the renin-angiotensin system were compared. In a 1-year study, 32 patients with essential hypertension were randomized to treatment with either the converting enzyme inhibitor lisinopril or the calcium antagonist isradipine; hydrochlorothiazide could be added. Blood pressure (BP) decreased significantly (p less than 0.001) and similarly in the 2 treatment groups. Left ventricular (LV) mass was already significantly reduced after 16 weeks of treatment (p less than 0.001) and remained decreased thereafter, with no difference in the response to the 2 treatment regimens. The change in LV mass was related to the decrease in systolic BP for the total study group (p less than 0.001) and for each treatment group separately. During the 3-week run-out period on placebo, BP and LV mass increased again (p less than 0.01). Afterload decreased during active treatment (p less than 0.001), and fractional shortening of the LV internal diameter was significantly increased (p less than 0.01) to a similar extent in both groups. The ratio of peak mitral flow velocities during atrial contraction and early filling was reduced after 1 year of active treatment in the total study group (p less than 0.01); this change was similar in both groups. The data suggest that the regression of LV mass during antihypertensive therapy is mainly related to the decrease in systolic BP.

Adult

The pathophysiology of idiopathic mitral valve prolapse.

Left ventricular structure, function, and the coronary circulation were studied in a subset of patients with mitral valve leaflet prolapse. This group of 26 patients (21 females, five males, with mean age of 46 years), had the syndrome identified as idiopathic mitral valve prolapse (IMVP), which was characterized by a systolic click-murmur, clinical symptoms that were highly variable in duration and intensity, angiographically-documented mitral prolapse, and no obvious associated systemic or cardiovascular disease. Mitral regurgitation was of moderate degree in four, mild in 14, and absent in eight. The left ventricular (LV) end-diastolic volume index was elevated in ten of 25 (40%), the LV mass index was elevated in six of 17 (35%), but the LV anterior wall thickness was increase in only one of 17. Three major patterns of ventricular contraction were identified: 1) normal in seven; 2) abnormal, usually an inferior deformity and/or anterior asynergy, in eight; and 3) hyperkinetic in 11. Normal resting left ventricular function, assessed as an ejection fraction greater than 55%, was present in 17 of 25 (68%). Selective coronary arteriography was essentially normal in all 25 patients studied. An ischemic ECG response was detected during only one of 12 maximal treadmill exercise tests and in none of ten atrial pacing stress tests (AP). Myocardial lactate extraction did not change significantly during AP in six patients. We conclude that cardiomyopathy does not appear to be a primary cause or an important associated component of the IMVP syndrome. Abnormalities of the coronary circulation or of myocardial metabolism were not demonstrated by available methods. A proposed pathophysiological mechanism to explain the clinical and angiographic findings in IMVP is discussed.

Adult

The cardiac functional reserve in elderly hypertensive patients with abnormal diurnal change in blood pressure.

OBJECTIVE: To evaluate the left ventricular function of hypertensive patients with abnormal diurnal change in blood pressure. DESIGN: We compared left ventricular structural and functional characteristics between hypertensive patients with a normal diurnal change in blood pressure (H2 group) and those with a nocturnal blood pressure increment (H1 group) using echocardiography. METHODS: The study group consisted of 36 hypertensives and 16 normotensives whose 24-h ambulatory blood pressure monitorings were measured non-invasively. The hypertensive group was subdivided into the H1 group, consisting of 11 patients (76 +/- 7 years), and the H2 group with 25 patients (73 +/- 7 years). The normotensive control group had a mean age of 73 +/- 6 years. Echocardiographic examinations were performed before and at the end of isometric exercise (handgrip for 3 min) and isoproterenol infusion (0.02 micrograms/kg per min for 5 min). RESULTS: The left ventricular mass index in the H1 group was significantly greater than in the H2 or control group. Left ventricular fractional shortening (LVFS) at rest in the H1 group was also significantly greater than in the other two groups. However, the peak late: early diastolic filling ratio, which indicated diastolic function, significantly deteriorated in the H1 group compared with the H2 and control groups. Furthermore, changes in LVFS after isometric exercise in the H1 group were more suppressed than in the H2 or control group. In addition, a significantly lower increment in LVFS after isoproterenol was observed in the H1 group compared with the H2 or control group. CONCLUSION: The H1 group had greater left ventricular mass and impaired left ventricular functional reserve than the H2 group.

Aged

Left ventricular structure and determinants in normotensive offspring of essential hypertensive parents.

OBJECTIVE: To assess whether currently normotensive offspring of essential hypertensive parents may have alterations in left ventricular mass (LVM) and function, and how these relate to some potential determinants. DESIGN AND METHODS: Echocardiographical indices of LVM (assessed by two-dimensional guided M-mode echocardiogram), 'clinic' blood pressure and daytime ambulatory blood pressure profiles, blood pressure responses to dynamic and isometric exercise testing, haematocrit, plasma and 24-h urinary electrolytes and catecholamines, and plasma angiotensin II were assessed on a defined Na+ intake in 31 normotensive lean sons of essential hypertensive parents (OHYP group) and 30 body mass index- and age-matched sons of normotensive parents (ONORM group). RESULTS: Clinic supine systolic blood pressure was higher in the OHYP than the ONORM group, but clinic diastolic and daytime ambulatory mean blood pressures, blood pressure loads and blood pressure during dynamic or isometric exercise did not differ significantly. LVM index (LVMI), interventricular septum thickness (IVST), posterior wall thickness (PWT), the IVST:PWT ratio, ejection fraction, fractional shortening, cardiac index and measured biochemical variables also did not differ significantly between groups. In the whole study population the LVMI correlated positively with the body mass index and negatively with plasma noradrenaline. CONCLUSIONS: In young lean men with one essential hypertensive parent and blood pressure still in the normal range, left ventricular structure and systolic function, as assessed by echocardiography, seem to be often unaltered and appropriate relative to the existing body habitus and blood pressure. Moreover, an early tendency for increasing resting blood pressure in genetically hypertension-prone humans may be more apparent under clinic than usual ambulatory conditions, whereas the blood pressure reactivity to physical stress seems to be largely normal at this stage.

Adult

Comparison of ketanserin and celiprolol on regression of left ventricular hypertrophy in older hypertensive patients.

The effects of ketanserin, a specific serotonin2-receptor agonist, and celiprolol, a new, highly cardioselective beta 1 blocker with partial beta 2 agonist activity and peripheral vasodilating properties, on left ventricular (LV) structure and function were assessed in 60 older hypertensive patients (greater than 55 years) with clinical LV hypertrophy (LV mass index greater than 130 g/m2). The patients were studied using echocardiography after 1 month of placebo treatment, and 6 and 18 months of monotherapy with active drug. Ketanserin and celiprolol lowered blood pressure to normal levels. Heart rate did not change with ketanserin and fell moderately (-5%) with celiprolol (p less than .001). Regression of LV hypertrophy was achieved with the use of either medication (p less than .0001), although the magnitude of reduction in LV mass was greater with celiprolol at both 6 months (-10% vs -5%, p = .001) and 18 months (-13% vs -7%, p = .002). While LV volume did not change with either drug, celiprolol tended to decrease it, resulting in a 5% reduction in cardiac index (p = .01), which was associated with mild bradycardia. Ketanserin did not change LV ejection fraction, whereas celiprolol caused a slight (1.5%) long-term improvement (p = .003). Systolic wall stress and total peripheral resistance decreased with both agents (p less than .01), with no between-group differences. In conclusion, anti-hypertensive treatment of older persons with ketanserin or celiprolol achieves regression of LV hypertrophy without associated deleterious effects on LV function.

Adrenergic beta-Antagonists

Failure of short-term nutritional convalescence to reverse the adverse hemodynamic effects of protein-calorie malnutrition in dogs.

We previously reported that protein-calorie malnutrition (PCM) exerts adverse hemodynamic effects on left ventricular (LV) structure and function. In the present experiments, we tried to determine the duration of these adverse effects by inducing significant weight loss in matched beagle dogs followed by a short-term course of nutritional repletion. Following restitution of initial body weight, the animals were placed on total cardiopulmonary bypass and an isovolumetric LV preparation was established to determine baseline LV function compared with matched animals that remained normally-nourished, and with a third group in which the effects of PCM were not reversed. Decreases in LV compliance persisted following refeeding as did the decreases in the first derivative of LV pressure (LV dp/dt). Although animals re-fed ordinary diets following acute weight loss restored normal concentrations of myocardial glycogen, cardiac abnormalities persited for more than one month following refeeding. These results suggest that the adverse effects of semistarvation on LV functions cannot be completely reversed by short-term refeeding.

Animals

Home blood pressure telemonitoring reveals race-specific patterns of target organ damage.

BACKGROUND: Racial differences in cardiac and renal target organ damage (TOD) may persist at comparable blood pressure levels. This study compared TOD in high-risk, non-African-American Black and White patients in relation to the home blood pressure (HBP). METHODS: UPRIGHT-HTM (NCT04299529) is an ongoing international trial comparing risk stratification strategies in asymptomatic patients, aged 55-75 &#x200a;years, with &#x2265;5 risk factors. Patients engage in HBP telemonitoring (OMRON HEM 9210-T). After 34.7&#x200a;months (median), 287 Black and 154 White patients underwent echocardiography. At baseline, their chronic kidney disease (CKD) grade was assessed by cross-classification of the race-free estimated glomerular filtration rate and albuminuria (2024 KDIGO guideline). HBP was stratified by the 2024 ESC thresholds. Linear and logistic regression models, including a race-by-HBP interaction term, were applied to assess associations with the home systolic HBP. RESULTS: The number of HBP readings was 252 215. Median systolic/diastolic HBP was 127/77&#x200a;mmHg with 142 patients (32.2%) having home hypertension. Fewer Black patients received statins or combination therapy for hypertension or diabetes. Among nonhypertensive White compared to Black patients, left atrial dimensions, mitral annular s', and stroke volume had a steeper slope in relation to systolic HBP. All patients had concentric left ventricular remodeling, but only 4 Black and 13 White patients had an ejection fraction&#x200a;<&#x200a;50%. CKD grade was worse in Black than White patients without association with HBP. CONCLUSIONS: TOD primarily affects the kidney in Black and the heart in White patients. Intensifying pharmacological treatment in sub-Saharan Africa, including antihypertensives, lipid-lowering agents, antidiabetic medications, and aspirin, should create an opportunity for improved overall cardiovascular and metabolic prevention.

Aged

Hemodynamic and pathological results from experimentally induced left ventricular hypertrophy in the rabbit.

Many studies of ventricular structure and function of the hypertrophied cardiac muscle have been performed using a model of right ventricular hypertrophy because a reliable experimental model for the chronically hypertrophied left ventricle was not available. Adult rabbits underwent thoractomy with placement of an ameroid band on the proximal aorta. The ameroid band closed to a maximal extent at 9 days. Systolic gradients were measured at 3 weeks. 37 animals (group I) were sacrificed at an average of 7 weeks, and 5 (group II) at 18 weeks. Specific cardiac chambers were weighed. The average left ventricular weight expressed as a percentage of body weight of control animals was 0.13 +/- 0.01 compared to group I 0.17 +/- 0.04 (P = 0.001) and group II 0.23 +/- 0.04. Hemodynamic data revealed significant aortic outflow obstruction with systolic gradients averaging at least 50 mm Hg. Left ventricular end-diastolic pressures were elevated in 13 of 29 animals compatible with left ventricular failure. These results indicate that this technique affords a reliable experimental model for inducing biventricular hypertrophy which can be evaluated hemodynamically.

Animals

The influence of heart rate on pulmonary arterial-left ventricular pressure relationships at end-diastole.

Increased resistance to blood flow stemming from structural and functional abnormalities of the lungs may cause pressure in the pulmonary artery to exceed that in the left ventricle at the end of ventricular diastole. This study explores the possible contribution of heart rate to the diastolic pressure gradient observed in the presence of acutely induced hypoxia. Pulmonary hemodynamics were examined in mongrel dogs with chronic atrioventricular dissociation with and without hypoxia at two different heart rates and during sequential increments in heart rate while the animals breathed room air. Studies during sequential pacing indicate that heart rate was of greater importance than blood flow in determining the magnitude of the gradient. Heart rate has to be considered when the causes of pulmonary hypertension and the effects of drugs or other agents on the pulmonary circulation are being investigated.

Animals

Cardiac remodelling and dysfunction in cancer patients receiving cardiotoxic therapies: proteomic and metabolomic profiling.

BACKGROUND AND AIMS: The objective of this study was to define the relationships between the circulating proteome and metabolome with cardiac structure and function in patients with breast cancer receiving cardiotoxic therapies. METHODS: Proteomics and metabolomics profiling was performed in a longitudinal, prospective cohort study of breast cancer patients receiving anthracyclines and/or trastuzumab, using the Olink Explore 3072 platform and rapid liquid chromatography-mass spectrometry, respectively. Multivariable linear mixed-effect models evaluated the contemporaneous (same visit) and lagged (subsequent visit) associations between repeated measures of individual proteins or metabolites with quantitative echocardiographic measures of cardiac structure [left ventricular (LV) mass and left atrial volume index] and function [LV ejection fraction (LVEF), longitudinal and circumferential strain, E/e', and ventricular-arterial coupling]. Cox regression and pathway enrichment analyses were conducted for biomarkers demonstrating significant associations with cardiac function. RESULTS: Across 547 breast cancer participants (median age 50 years), 203 unique proteins and 16 unique metabolites were significantly associated with measures of cardiac structure and function in contemporaneous and lagged analyses. Notably, cathepsin C was associated with LVEF [false discovery rate (FDR), P = .017], longitudinal strain (FDR, P = .046), left atrial volume index (FDR, P = .035), and incident cardiac dysfunction, defined by an LVEF decline &#x2265;10% to <50% (hazard ratio .61, 95% confidence interval .41, .90). The 147 proteins associated with cardiac function were enriched in biological processes reflective of protein deubiquitination, protein modification by small protein removal, macromolecule catabolic processes, and global metabolic pathways. Individual metabolites significantly associated with cardiac function (LVEF, longitudinal strain) included n-acetylglutamine, aspartic acid, acetylasparagine, alanyl-alanine, and prolyl-glycine (FDR, P-value < .001), and belonged to amino acids and derivatives and peptides. CONCLUSIONS: These findings provide translational insights into cancer therapy-related cardiac dysfunction and remodelling and identify potential new biomarkers of cardiotoxicity. There is an important need for validation of these findings and a deeper understanding of the biology of these biomarkers.

Humans

Ventricular-arterial coupling is preserved in prematurely born 11-year-old children but calls for life-long prevention of hemodynamic deterioration.

BACKGROUND: Premature birth disrupts the intra-uterine structural and functional maturation of the left ventricle (LV) and arteries. The study investigated the impact of premature birth on ventricular-arterial coupling (VAC), a potential precursor of cardiovascular disease in adulthood. METHODS: This case-control study in Northern Belgium (2011-2016) included 93 extremely-low-birth-weight (ELBW) cases and 87 sex and age-matched term-born controls. Main outcomes included SBP and DBP, central arterial properties, echocardiographic structure and function, and VAC. RESULTS: Compared with controls, cases were shorter by 4.1&#x200a;cm [95% confidence interval (95% CI): 1.3-7.0] and lighter by 4.1&#x200a;kg (95% CI: 1.3-6.9). Cases had higher central SBP/DBP (+7.3/3.0&#x200a;mmHg; 95% CI: 4.7-9.9/1.1-4.8), lower left ventricular end-diastolic and end-systolic dimensions, and 9.2&#x200a;g (95% CI: 3.7-14.6) lower left ventricular mass. Left ventricular volumes and mass correlated with body size without significant between-group differences ( P &#x200a;&#x2265;&#x200a;0.12). Cardiac output was 0.38&#x200a;l/min lower in cases, who also had higher arterial resistance (29.5 vs. 24.4&#x200a;mmHg&#x200a;&#xd7;&#x200a;min/l) and augmentation ratio (1.10 vs. 1.05). The tension-time index was 231&#x200a;mmHg &#xd7; ms (95% CI: 128-335) higher in cases. Ea and Ees were higher in cases (0.40 and 0.65&#x200a;mmHg/ml, respectively), but VAC did not differ between groups ( P &#x200a;=&#x200a;0.48). CONCLUSION: Compensatory mechanisms maintain the anatomical and functional integrity of the cardiovascular system in ELBW youth, but mask their vulnerability to cardiovascular disease in adulthood and necessitate careful follow-up during adolescence.

Humans

Sex, cardiac hypertrophy and diurnal blood pressure variations in essential hypertension.

OBJECTIVE: To test the hypothesis of a difference between men and women in the left ventricular hypertrophic response to diurnal variations of ambulatory blood pressure in essential hypertension. DESIGN: Non-invasive ambulatory blood pressure monitoring and echocardiography in untreated hypertensive patients and healthy normotensive subjects. SETTING: Community-based ambulatory population in tertiary care centers. PATIENTS: Two hundred and sixty hypertensive patients and sixty-three healthy normotensive subjects. MAIN OUTCOME MEASURE: Patients with average daytime systolic blood pressure (SBP) and diastolic blood pressure (DBP) falling by less than 10% during the night were defined as non-dippers, the others as dippers. RESULTS: In the hypertensive group, dippers and non-dippers did not differ, in either gender, in several covariates possibly affecting left ventricular structure, including daytime ambulatory blood pressure, prevalence of white coat hypertension, age, body mass index, family history and known duration of hypertension, funduscopic changes, diabetes, alcohol consumption and renal function. Left ventricular mass (LVM) did not differ between dippers and non-dippers in hypertensive men whilst in hypertensive women it was significantly lower in dippers than in non-dippers. This sex difference held for all quartiles of the distribution of mean daytime blood pressure. In hypertensive women there was an inverse correlation between LVM and the per cent reduction of SBP and DBP from day to night, but this relationship was absent in hypertensive men. Other indices of left ventricular structure differed between dippers and non-dippers in both genders, as did LVM. CONCLUSIONS: For any level of daytime ambulatory blood pressure, a reduction of SBP and DBP by less than 10% from day to night identifies a subset of hypertensive patients at increased risk of left ventricular hypertrophy only in the female gender. These data suggest that, compared with men, hypertensive women require a longer duration of exposure to high blood pressure levels during the 24 h to develop left ventricular hypertrophy.

Blood Pressure

Changes in cardiac myosin acetylation disrupt the super-relaxed state in genotype-negative hypertrophic cardiomyopathy with type 2 diabetes.

BACKGROUND: Patients with hypertrophic cardiomyopathy (HCM) and type 2 diabetes (T2D) have a more severe cardiac phenotype and worse clinical course than non&#x2011;diabetic patients. To identify how T2D aggravates the disease and whether the most abundant cardiac protein, myosin, is involved, we combined functional, structural and mass spectrometry analyses of human samples. METHODS: Left ventricular septal myectomy samples from genotype&#x2011;negative (G-) HCM patients without T2D (G-&#x2009;, N&#x2009;=&#x2009;19) and with T2D (G-T2D, N&#x2009;=&#x2009;15) were analyzed mainly using fluorescent ATP chase experiments, small&#x2011;angle X&#x2011;ray diffraction and targeted myosin heavy chain proteomics. RESULTS: Mant&#x2011;ATP chase measurements showed a lower fraction of myosin heads in the energy&#x2011;conserving super&#x2011;relaxed (SRX) state in G-T2D compared to non-diabetic myocardium. In parallel, X&#x2011;ray diffraction showed trends toward structural alterations in myosin organization in G-T2D tissue, consistent with altered OFF/ON state equilibrium. Targeted mass spectrometry identified hyperacetylation of several myosin lysine residues in G-T2D, including K847 within the S2 region. All&#x2011;atom molecular dynamics simulations indicated that K847 acetylation disrupts stabilizing electrostatic interactions in the interacting&#x2011;heads motif, which is associated with the OFF state. CONCLUSIONS: Disruption of myosin super&#x2011;relaxation emerges as a central cellular defect in G-T2D HCM myocardium and can be mechanistically linked to site&#x2011;specific myosin hyperacetylation at K847, providing a potential therapeutic target for genotype&#x2011;negative HCM with T2D.

Humans

Cardiovascular mass and ventricular function after celiprolol in Wistar-Kyoto and spontaneously hypertensive rats.

OBJECTIVE: The effects of a new beta 1 adrenergic receptor blocking agent with beta 2 receptor agonistic properties on cardiovascular mass, left ventricular function, and aortic distensibility were studied in Wistar-Kyoto (WKY) and spontaneously hypertensive (SHR) rats. METHODS: 20 male SHR and 20 male WKY rats (10 treated and 10 untreated) aged 22 weeks were studied after three weeks of treatment. Cardiovascular mass was measured and left ventricular function was assessed using electromagnetic flowmetry while rapidly infusing whole blood at pharmacologically reduced mean arterial pressure and at pretreatment arterial pressure levels. Aortic distensibility was assessed by obtaining pressure-volume relationships in isolated aortic segments. RESULTS: Mean arterial pressure was reduced without changing cardiac output in SHR (p less than 0.01); it remained unchanged in WKY despite reduced cardiac output. Most noteworthy, and like no other agent studied to date, celiprolol significantly reduced both left and right ventricular as well as aortic mass in both WKY and SHR. Despite these similar mass reductions, celiprolol improved left ventricular function (p less than 0.01) and aortic distensibility (p less than 0.05) only in the SHR, a function maintained even when mean arterial pressure was increased abruptly to pretreatment levels. CONCLUSIONS: Unlike other beta receptor blockers (or any other agent studied in the SHR), celiprolol was effective in reducing mass of right and left ventricles and of aorta; decreasing mean arterial pressure through a fall in total peripheral resistance; and improving left ventricular function and aortic distensibility in the SHR. In contrast, while these structural changes were also produced in WKY, they were not associated with similar functional responses. These findings provide further support for the thesis of a structural and haemodynamic dissociation in antihypertensive therapy.

Adrenergic beta-Antagonists

Proteome organ aging and cardiometabolic risk in a population at risk for heart failure.

BACKGROUND: Biological aging varies across individuals and tissues, influencing chronic diseases, including heart failure (HF). Emerging proteome techniques enable quantification of organ-specific aging acceleration (OAA), but whether OAA relates to HF severity and differs by sex remains unclear. We aim to assess the sex-related association between OAA of heart, artery and kidneys and HF severity, and to investigate relevant cardiometabolic risk factors of organ aging. METHODS: In 556 participants from the HELPFul cohort, we estimated predicted biological age for heart, artery, and kidneys using plasma proteomics and calculated OAA as the deviation from chronological age. Associations between OAA and HF stage, echocardiographic parameters, and cardiometabolic risk factors were evaluated using regression models. Composite indices, including triglyceride-glucose body mass index (TyG-BMI), c-reactive protein-triglyceride glucose index and triglyceride-to-HDL cholesterol ratio were assessed for associations with advanced OAA. RESULTS: Mean age was 63&#x2009;&#xb1;&#x2009;9&#xa0;years; 65% were women. Patients were classified as HF stage A (35%), B (29%) and C/D (36%). Heart OAA was significantly associated with advanced HF (Stage C/D) in both sexes (OR&#x2009;=&#x2009;1.12, 95% CI 1.03 to 1.23 in women; OR&#x2009;=&#x2009;1.18, 95% CI 1.05 to 1.32 in men), while artery OAA was linked to HF only in women (OR&#x2009;=&#x2009;1.10, 95% CI 1.01 to 1.18). Multi-organ aging (&#x2265;&#x2009;2 organs with advanced OAA) conferred over three-fold higher odds of being in Stage C/D. Heart OAA correlated with impaired cardiac structure and function, particularly reduced ejection fraction in men and increased left ventricular mass index in both sexes. Diabetes emerged as the most relevant factor of artery and kidney OAA. TyG-BMI was significantly associated with advanced kidney OAA, only in women (z-scored OR&#x2009;=&#x2009;1.88, 95% CI 1.45 to 2.45). CONCLUSIONS: Proteome-derived organ aging correlates with HF severity, with possible sex-related patterns. Diabetes and higher TyG-BMI are associated with faster organ aging, which may reflect shared aging mechanisms between metabolic dysfunction and HF.

Humans

[The value of echocardiography in the diagnosis of cardiac diseases].

Single beam echocardiography is now an established diagnostic tool in non-invasive cardiology. The principle indications are valvular diseases, pericardial effusion, aneurysm of the ascending aorta, and congenital heart disease. In the absence of regional contraction disorders, left ventricular function can be assessed by the extent of systolic shortening of the left ventricular diameter. More recently, two-dimensional echocardiography has made a very significant contribution to anatomical and functional evaluation of the heart and the great vessels, since the cardiac structures can be visualized in various cross-sections. This technique is especially helpful for the assessment of left ventricular regional contraction disturbances, the diagnosis of dysfunction of artificial valves and bioprotheses, the detection of dissecting aneurysm, and the estimation of mitral valve area in mitral stenosis. Since various left ventricular axes can be determined, the quantitation of left heart volumes appears to be within the capability of the two-dimensional technique.

Aortic Aneurysm

Myocardial collagen remodeling and left ventricular diastolic function.

1. The myocardial collagen matrix is an active participant in determining ventricular architecture and diastolic function, and myocardial structural integrity and mechanical properties. It consists of a network of fibrillar collagen which is intimately related with the myocyte, myofibril and muscle fiber as well as the coronary vasculature. Consisting primarily of collagen types I and III, this material exhibits a high tensile strength which, even though normally present in relatively small amounts, plays an important role in the behavior of the ventricle during diastole. 2. Removal of less than half of the normal amount of collagen results in a dilated ventricle with increased compliance. Collagen degradation of this magnitude and similar myocardial and ventricle with increased compliance. Collagen degradation of this magnitude and similar myocardial and ventricular histologic and functional alterations are evident during ischemia and in dilated cardiomyopathy. Thus, it would appear that a chronic change in the shape and size of the heart must be preceded by alterations in the interstitial collagen matrix. 3. With elevations in the circulating levels of angiotensin and/or mineralocorticoids, the hypertrophic response of the myocardium to the accompanying hypertension includes a progressive remodeling of the collagen component. Typically there is an increase in collagen concentration, thickening of existing fibrillar collagen and the addition of new collagen at all levels of the matrix. The consequences of this remodeling are an adverse alteration of the passive mechanical properties of the myocardium and LV diastolic dysfunction. This pathophysiologic aspect of the hypertrophic process is independent of the concomitant remodeling of the myocyte.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

Progression to left ventricular dilatation in patients with hypertrophic obstructive cardiomyopathy.

Congestive heart failure with dilated left ventricle developed in two patients with symptomatic hypertrophic obstructive cardiomyopathy. Both patients previously underwent cardiac surgery for relief of their outflow obstruction. Alterations in structure and function of the left ventricle during their episode of cardiac failure and thereafter were documented by echocardiography. The findings suggest that progression to left ventricular dilatation is a potential complication in patients with hypertrophic obstructive cardiomyopathy.

Cardiomyopathy, Hypertrophic