Late-onset renal hypertension in old rats alters myocardial microvessels

1990 ◽  
Vol 259 (6) ◽  
pp. H1681-H1687 ◽  
Author(s):  
R. J. Tomanek ◽  
M. R. Aydelotte ◽  
C. A. Butters
Keyword(s):  
Late Onset ◽  
Renal Hypertension ◽  
Age Groups ◽  
Left Ventricular ◽  
Numerical Density ◽  
Middle Aged ◽  
Absolute Increase ◽  
The Mean ◽  
Microvascular Alterations ◽  
O2 Supply

We tested the hypothesis that late-onset hypertension in middle-aged (15 mo) and senescent (24 mo) rats would adversely affect the coronary microvasculature. Morphometric analyses were performed on coronary capillaries and arterioles from rats with one-kidney, figure-8 renal wrap hypertension of 3-mo duration. Compared with control rats, wall-to-lumen ratios of arterioles with lumen diameters less than 25 microns were higher in the two hypertensive groups by approximately 30%; larger arterioles did not show consistent intergroup differences. A comparison of the two control groups revealed that wall-to-lumen ratio of arterioles with lumen diameters less than 50 microns tended to be greater in the senescent rats. Capillary numerical density was markedly reduced in the hypertensive animals of both age groups and caused an increase in the mean Krough cylinder radius and in the mean capillary domain. The latter increased by 28-63%; the largest increment occurred in the endomyocardium of the senescent group. A trend toward increased heterogeneity of capillary spacing was also noted in the hypertensive rats. The observed microvascular alterations occurred in the absence of an absolute increase in left ventricular mass but in the presence of cardiocyte hypertrophy. Thus the decrements in capillary numerical density are not only due to inadequate growth but reflect an absolute reduction in the number of these vessels associated with cardiocyte loss. It is concluded that late-onset hypertension in middle-aged and senescent rats is characterized by left ventricular wall remodeling that includes microvascular alterations that would be expected to limit maximal myocardial flow and O2 supply to the cardiocyte.

Late onset renal hypertension in old rats alters left ventricular structure and function

1992 ◽  
Vol 262 (2) ◽  
pp. H531-H538 ◽  
Author(s):  
R. J. Tomanek ◽  
M. R. Aydelotte
Keyword(s):  
Cellular Response ◽  
Late Onset ◽  
Renal Hypertension ◽  
Left Ventricular ◽  
Lv Function ◽  
Stroke Index ◽  
Sprague Dawley ◽  
Compensatory Response ◽  
Absolute Increase ◽  
Old Rats

This study was designed to test the hypothesis that the left ventricle of the senescent rat has a limited compensatory response to late onset hypertension. Data were obtained from middle-aged (15 mo) and senescent (24 mo) Sprague-Dawley rats either 1 or 3 mo after the initiation of one-kidney figure-8 renal wrap (Grollman) hypertension. Peak left ventricular (LV) function assessed during acute volume expansion was not markedly affected 1 mo after induction of hypertension with the exception of a decrement in the acceleration of aortic flow (dF/dt) in the senescent hypertensive group. Three months after the surgery was performed, peak LV function (stroke index, stroke volume/g LV, and dF/dt) was depressed in the senescent hypertensive rats, compared with the controls. In contrast, these indexes in the 15-mo-old rats were similar in the experimental and control groups after either 1 or 3 mo of hypertension. Developed pressure, however, was not compromised by hypertension at either age. Cardiocyte hypertrophy due to pressure overload occurred in both age groups but to a greater extent in the senescent group. This cellular response did not cause an absolute increase in LV mass and was associated with endomyocardial foci of cellular degeneration and fibrosis suggestive of cell loss. Mitochondria-to-myofibril volume ratios were not significantly altered in the experimental groups at either age, thus the cellular hypertrophy in these rats was characterized by uniform organelle growth. These data support two important conclusions regarding late onset hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Clinical features and outcome of Covid-19 in individuals without Comorbidities. Do children have the advantage?

2021 ◽  
Vol 8 (2) ◽  
pp. 88-93
Author(s):  
Dr. Abhishek Kumar ◽  
◽  
Dr. Nilu Kumari ◽  
Dr. Ranjeet Kumar Singh ◽  
Dr. Alok Kumar ◽  
...  
Keyword(s):  
Severe Disease ◽  
Age Groups ◽  
Asymptomatic Infection ◽  
Healthy Individuals ◽  
Adult Group ◽  
Middle Aged ◽  
History Of ◽  
Adults And Children ◽  
The Mean ◽  
Respiratory Complaints

Objective: Information regarding clinical characteristics and the natural course of COVID-19amongst individuals without comorbidities is scarce. We therefore conducted a retrospectiveobservational study to decipher the disease profile in two different age groups, middle-aged (40-59years) and children (up to 12 years). Method: Study was conducted by reviewing the medicalrecords of all patients in the desired age groups and excluding all those with preexisting illness(called comorbidities). Result: A total of 154 and 27 patients were enrolled and studied in themiddle-aged adults and children group respectively. Males dominated in both groups with a sex ratioof 2.9 in adults and 1.7 in children. Most of the children (92.5%) had a history of exposure from aninfected family member, while in the adult group history of contact was present in 71.4% ofpatients.62.9% of children had an asymptomatic infection which was significantly higher than 22.8%in adults. Cough and fever were the most common symptoms in both age groups, but adults weremore likely to have respiratory complaints when compared with children.11 (7.1%) patients in theadult group had severe disease while in the children group none had severe disease. Similarly in theadult group 11 patients required ICU admission, but none in the children group. The mean durationof RTPCR positivity was similar in both groups. There was 1 (0.6%) expiry in the adult groupwhereas none in children. Conclusion: Healthy individuals in both middle-aged and children grouptend to have milder disease and both harbour the virus for the almost same duration but adults aremore symptomatic in comparison to children and hence children are more likely to be potentialasymptomatic carrier and transmitter of infection.

P337Natural history, reversibility and arrhythmias associated with truncating titin variants in dilated cardiomyopathy

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
C R Vissing ◽  
T B Rasmussen ◽  
M S Olesen ◽  
L N Pedersen ◽  
A Dybro ◽  
...  
Keyword(s):  
Dilated Cardiomyopathy ◽  
Medical Therapy ◽  
Ventricular Arrhythmias ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Reverse Remodeling ◽  
Absolute Increase ◽  
The Mean

Abstract Background Truncating genetic variants in titin (TTNtv) are identified in 15–25% of patients with primary dilated cardiomyopathy (DCM). Previous genotype/phenotype studies have reported conflicting results regarding disease severity and pathologic features associated with TTNtv. Purpose To investigate the natural history, reversibility and burden of arrhythmias associated with TTNtv in a Danish cohort with long-term follow-up. Methods Patients with DCM, recruited from two Danish tertiary centers, were included based on the presence of a TTNtv in a cardiac expressed titin exon. Data on patients' medical history including symptoms, demography, family history, comorbidities, treatment, ECG features, and echocardiograms were registered. Outcome data including all-cause mortality, need of heart transplantation (HTX) or left ventricular assist device (LVAD), and presence of ventricular and supraventricular arrhythmias were registered. Left ventricular reverse remodeling (LVRR) was defined as an absolute increase in left ventricular ejection fraction (LVEF) ≥10% points or normalization. Results A total of 104 patients (71 men, 69%; 72 probands) with definite TTNtv-DCM were included. The mean age at DCM diagnosis was (mean±SD) 45±13 years (43±13 for men; 49±14 for women, p<0.04) and median follow-up was 8.1 years. The mean LVEF was 28±13% at time of diagnosis (26±12% for men; 30±13% for women, p=0.173). During follow-up, 31 patients (30%; 24 men) died or needed HTX/LVAD. Medical therapy was associated with LVRR in 79% of patients 3.6 years after diagnosis. LVRR was maintained long-term in 64% of patients. Women had a better response to medical therapy compared to men (mean LVEF increase 19%; vs 15% in men, p<0.04). Atrial fibrillation/flutter was observed in 40% of patients and ventricular arrhythmias in 23% of patients. Men had an earlier occurrence of both supraventricular and ventricular arrhythmias (p=0.005) with half of the men having experienced an arrhythmia at the age of 54 years. Freedom from arrhythmias with age Conclusion TTNtv leads to a DCM phenotype associated with a marked gender-difference in age at DCM diagnosis and high burden of both supraventricular and ventricular arrhythmias. Importantly, the DCM-TTNtv phenotype was associated with a high degree of reversibility of systolic function following medical therapy.

scholarly journals A Novel Myosin Essential Light Chain Mutation Causes Hypertrophic Cardiomyopathy with Late Onset and Low Expressivity

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Paal Skytt Andersen ◽  
Paula Louise Hedley ◽  
Stephen P. Page ◽  
Petros Syrris ◽  
Johanna Catharina Moolman-Smook ◽  
...  
Keyword(s):  
Hypertrophic Cardiomyopathy ◽  
Light Chain ◽  
Late Onset ◽  
Large Family ◽  
Left Ventricular ◽  
Cascade Screening ◽  
Essential Light Chain ◽  
Mutation Carriers ◽  
Genes Encoding ◽  
The Mean

Hypertrophic cardiomyopathy (HCM) is caused by mutations in genes encoding sarcomere proteins. Mutations inMYL3, encoding the essential light chain of myosin, are rare and have been associated with sudden death. Both recessive and dominant patterns of inheritance have been suggested. We studied a large family with a 38-year-old asymptomatic HCM-affected male referred because of a murmur. The patient had HCM with left ventricular hypertrophy (max WT 21 mm), a resting left ventricular outflow gradient of 36 mm Hg, and left atrial dilation (54 mm). Genotyping revealed heterozygosity for a novel missense mutation, p.V79I, inMYL3. The mutation was not found in 300 controls, and the patient had no mutations in 10 sarcomere genes. Cascade screening revealed a further nine heterozygote mutation carriers, three of whom had ECG and/or echocardiographic abnormalities but did not fulfil diagnostic criteria for HCM. The penetrance, if we consider this borderline HCM the phenotype of the p.V79I mutation, was 40%, but the mean age of the nonpenetrant mutation carriers is 15, while the mean age of the penetrant mutation carriers is 47. The mutation affects a conserved valine replacing it with a larger isoleucine residue in the region of contact between the light chain and the myosin lever arm. In conclusion,MYL3mutations can present with low expressivity and late onset.

Age-Dependent Changes of Plasma Renin Concentration in Humans

1973 ◽  
Vol 45 (s1) ◽  
pp. 273s-278s ◽  
Author(s):  
K. Hayduk ◽  
D. K. Krause ◽  
W. Kaufmann ◽  
R. Huenges ◽  
U. Schillmöller ◽  
...  
Keyword(s):  
Sodium Intake ◽  
Post Partum ◽  
Age Groups ◽  
Plasma Renin ◽  
Relative Increase ◽  
Upright Posture ◽  
Healthy Children ◽  
Absolute Increase ◽  
Plasma Renin Concentration ◽  
The Mean

1. Plasma renin concentration (PRC) in newborns greatly exceeded PRC in children and adults. PRC in cord plasma of newborns was higher than peripheral venous PRC in their mothers. PRC in the newborns increased further in the first 48 h post partum and then gradually decreased. 2. The mean PRC of healthy children and adults on free sodium intake decreased with age by an exponential function. 3. The absolute increase of PRC in response to upright posture (PRCupright — PRCrecumbent) decreased with age. The relative increase of PRC in response to upright posture (PRCuprjght:PRCrecumbent) remained unchanged with age, the PRC in upright posture being about twice the basal PRC in all age groups.

Reduced Efficacy of Volatile Anesthetic Preconditioning with Advanced Age in Isolated Rat Myocardium

2004 ◽  
Vol 100 (3) ◽  
pp. 589-597 ◽  
Author(s):  
Roman Sniecinski ◽  
Hong Liu
Keyword(s):  
Young Adult ◽  
Ischemic Preconditioning ◽  
Age Groups ◽  
Left Ventricular ◽  
Aged Rats ◽  
Middle Aged ◽  
Beneficial Effects ◽  
Anesthetic Preconditioning ◽  
Intracellular Ca ◽  
Developed Pressure

Background Ischemic preconditioning and anesthetic preconditioning (APC) are reported to decrease myocardial infarct size during ischemia-reperfusion injury. However, the beneficial effects of ischemic preconditioning have been shown to decrease with advancing age. Although the mechanisms of ischemic preconditioning and APC are thought to be similar, it is not known whether the beneficial effects of APC are also reduced in the aged myocardium. Methods Male Fischer 344 rats of three age groups (2-4, 10-12, and 20-24 months) were used. Hearts were Langendorff perfused. Six hearts in each age group were pretreated with 10 min of sevoflurane and a 5-min washout before 25 min of ischemia and 60 min of reperfusion. Six control hearts in each age group received no treatment before ischemia. Nuclear magnetic resonance was used to measure intracellular Na, intracellular Ca, and intracellular pH, respectively. Left ventricular developed pressure, creatine kinase, and infarct size were measured. Results Ischemia decreases intracellular pH and increases intracellular Na and intracellular Ca in all age groups. APC blunts the pH decreases in young adult and middle-aged rats, but not in aged rats. APC decreased intracellular Na and intracellular Ca accumulation during ischemia in young adult and middle-aged hearts. APC improved adenosine triphosphate recovery in young rats but not in aged rats. Creatine kinase and infarct sizes were significantly reduced and left ventricular developed pressure was improved with APC in the young adult and middle-aged groups but not the aged group. Conclusions The benefits of APC are significantly reduced with advanced age in an isolated rat heart model.

Cardiovascular Design after ‘Reversal’ of Long-Standing Renal Hypertension in Rats

1979 ◽  
Vol 57 (s5) ◽  
pp. 19s-21s ◽  
Author(s):  
Y. Lundgren ◽  
Lilian Weiss
Keyword(s):  
Mean Arterial Pressure ◽  
Arterial Pressure ◽  
Renal Artery ◽  
Renal Hypertension ◽  
Left Ventricular ◽  
Resistance Vessels ◽  
Mean Pressure ◽  
The Mean ◽  
Normotensive Control

1. After 4–5 months of renal hypertension in rats renal artery ‘declipping’ was performed. Eight weeks afterwards paired hindquarter perfusions were performed on the declipped rats and normotensive control rats, exploring the relationships between mean arterial pressure and flow, from maximal vasodilatation to maximal vasoconstriction, induced by graded noradrenaline infusions. Left ventricular weights were measured. 2. Declipping caused a fall in mean arterial pressure from 180 to 135 mmHg, though still after 8 weeks the mean pressure was 19% higher than in normotensive control rats. 3. All parameters reflecting design and reactivity of the resistance vessels and left ventricular weight decreased significantly, but not as much as mean arterial pressure, and were still significantly increased compared with those of control rats. 4. Thus neither mean arterial pressure nor cardiovascular design was normalized 8 weeks after ‘reversal’ of long-standing renal hypertension, in contrast to short-standing renal hypertension where both are completely normalized 3 weeks after declipping.

Amelioration of effects of hypertension and diabetes on myocardium by cardiac glycoside

1992 ◽  
Vol 262 (3) ◽  
pp. H734-H742
Author(s):  
J. M. Capasso ◽  
E. Puntillo ◽  
B. Halpryn ◽  
G. Olivetti ◽  
P. Li ◽  
...  
Keyword(s):  
Ventricular Remodeling ◽  
Diastolic Pressure ◽  
Renal Hypertension ◽  
Time Derivative ◽  
Left Ventricular Pressure ◽  
Wall Stress ◽  
Capillary Density ◽  
Left Ventricular ◽  
Numerical Density ◽  
Arterial Blood

To determine whether digoxin protects the myocardium during the initial phases of hypertension and diabetes combined, adult male Wistar rats with two-kidney, one-clip renal hypertension and streptozotocin-induced diabetes mellitus were treated with digoxin (500 micrograms.kg-1.day-1) by gavage for 10 wk immediately after the onset of hypertension and diabetes. Systemic arterial blood pressures, ventricular pressures, the first time derivative of left ventricular pressure, diastolic wall stress, and the quantitative analysis of the number and distribution of myocardial lesions and capillary density of the myocardium were measured. In comparison to untreated hypertensive-diabetic animals, digoxin-treated rats showed a lesser elevation in left ventricular end-diastolic pressure and diastolic and systolic wall stress despite comparable degrees of hypertension and blood glucose levels. In addition, chamber diameter was smaller and the diffusion distance for oxygen was within normal values in animals treated with this glycoside. However, the numerical density of the foci of replacement fibrosis was similar to that found in untreated hypertensive-diabetic animals. In conclusion, digoxin reduces the magnitude of ventricular remodeling and diastolic wall stress in this model of hypertension and diabetes.

Coronary blood flow in senescent rats with late-onset hypertension

1993 ◽  
Vol 264 (6) ◽  
pp. H1854-H1860
Author(s):  
R. J. Tomanek ◽  
M. R. Aydelotte ◽  
K. E. Anderson ◽  
R. J. Torry
Keyword(s):  
Vascular Resistance ◽  
Late Onset ◽  
Diastolic Pressure ◽  
Age Groups ◽  
Left Ventricular ◽  
Relative Reduction ◽  
Coronary Perfusion ◽  
Coronary Vascular Resistance ◽  
Fischer 344 Rats ◽  
Fischer 344

We tested the hypothesis that the imposition of hypertension late in life would markedly limit maximal myocardial perfusion (MP). Young adult (8 mo) and senescent (24 mo) Fischer 344 rats were studied 3 mo after one-kidney, figure-8 renal wrap hypertension (RH) was induced. Sham-operated rats served as controls (Con). Regional MP was determined with radioactive microspheres in conscious rats before and during maximal coronary vasodilation with infusion of dipyridamole. Systolic arterial pressure (SAP) was significantly elevated in both RH age groups during weeks 2-6 following surgery and then fell to normotensive levels. After 3 mo SAP (mmHg) was significantly lower in the senescent RH rats (125 +/- 5) compared with their controls (147 +/- 3). In senescent RH rats left ventricular (LV) end-diastolic pressure increased fivefold. LV mass increased with age but not with treatment. LV minimal coronary vascular resistance (MCVR, mmHg.ml-1.min-100 g) increased significantly both with age and treatment (8 mo: Con = 0.07 +/- 0.01, RH = 0.14 +/- 0.01; 24 mo: Con = 0.11 +/- 0.01, RH 0.17 +/- 0.02). Treatment affected similar changes in the right ventricular MCVR. LV endocardial-to-epicardial perfusion ratio during rest was lower in the senescent groups but was not altered by hypertension. These data indicate that 1) both aging and this model of hypertension compromise maximal coronary perfusion and reserve in Fischer 344 rats, and 2) aging is associated with an increase in coronary vascular resistance in both ventricles at rest and in a relative reduction in maximal endocardial perfusion in the left ventricle.

NFLUENCE OF DRUG THERAPY ON DYNAMICS STRUCTURAL AND FUNCTIONAL INDICATORS OF THE HEART IN PATIENTS WITH HEART FAILURE OF ISCHEMIC ORIGIN IN DIFFERENT AGE GROUPS

2020 ◽  
pp. 8-18
Author(s):  
Елена Владимировна Гостева ◽  
Ольга Александровна Осипова ◽  
Людмила Валентиновна Васильева ◽  
Сергей Васильевич Жемчужников ◽  
Наталия Анатольевна Коренькова
Keyword(s):  
Heart Failure ◽  
Left Ventricle ◽  
Ejection Fraction ◽  
Randomized Study ◽  
Age Groups ◽  
Right Ventricular Dysfunction ◽  
Left Ventricular ◽  
Control Group ◽  
Middle Aged ◽  
Aged Patients

Цель исследования заключалась в выявлении особенностей структурно-функционального ремоделирования миокарда у больных хронической сердечной недостаточностью пограничной (40-49%) фракцией выброса (ХСНпрФВ) в разных возрастных группах и их коррекции на основе фармакотерапии. Проведено открытое рандомизированное исследование с участием 168 больных ХСНпрФВ ишемического генеза, средний возраст - 62,5±10,7 лет. В зависимости от возраста они были разделены: 1 группа - возраст от 50 до 59 лет, средний - 54,2 ± 4,1 года; 2 группа - от 60 до 74 лет, средний - 66,4 ± 6,2 года. Средние дозы небиволола через 12 месяцев составили 8,55±1,75 мг, бисопролола - 8,45±1,65 мг, эплеренона - 48,25±2,25 мг. Больные ХСНпрФВ ишемического генеза вне зависимости от возраста, имеют достоверно большие размеры левого желудочка, левого предсердия по сравнению с контрольной группой. С возрастом нарастает степень гипертрофии левого желудочка, увеличивается относительная толщина стенок левого желудочка, индекс объем/масса левого желудочка, что свидетельствует о концентрическом ремоделировании левого желудочка в среднем и пожилом возрасте. Наиболее выраженную дисфункцию правого желудочка имели больные пожилого возраста. Нами установлено, что через 12 месяцев при добавлении к терапии эплеренона у больных отмечалось более выраженное достоверное снижение размеров левого желудочка, индекса сферичности и индекса объем/масса ЛЖ. Улучшение диастолической функции правого желудочка отмечено только на фоне комбинированной терапии небивололом с эплереноном в группе больных среднего возраста. В группах больных (как среднего, так и пожилого возраста), принимавших комбинацию небиволола и эплеренона, отмечен переход всех больных в класс ХСН с сохраненной фракцией выброса The aim of the study was to identify the features of structural and functional remodeling of the myocardium in patients with chronic heart failure with a middle range (40-49%) ejection fraction (HFmrEF) in different age groups and their correction based on pharmacotherapy. An open randomized study was conducted with the participation of 168 patients with HF, with an average age of 62.5±10.7 years. Depending on their age, they were divided: 1 group-age from 50 to 59 years, the average-54.2 ± 4.1 years; 2 group - from 60 to 74 years, the average-66.4 ± 6.2 years. Average doses of nebivolol after 12 months were 8.55±1.75 mg, bisoprolol-8.45±1.65 mg, eplerenone-48.25±2.25 mg. Patients with HFmrEF, regardless of age, have significantly larger sizes of the left ventricle and left atrium compared to the control group. With increasing age the degree of left ventricular hypertrophy, increased relative wall thickness of left ventricle, index volume/mass of the left ventricle, evidence of concentric remodelling of the left ventricle in middle and old age. Elderly patients had the most pronounced right ventricular dysfunction. We found that after 12 months, when eplerenone was added to therapy, patients had a more pronounced significant decrease in the size of the left ventricle, the sphericity index, and the LV volume/mass index. Improvement of diastolic function of the right ventricle was observed only in combination therapy with nebivolol and eplerenone in a group of HFmrEF middle-aged patients. In groups of patients (both middle-aged and elderly) who took a combination of nebivolol and eplerenone, the transition of all patients to the class of HF with a preserved ejection fraction was noted

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