Significant Cardiac Enlargement Research Articles

Unusual origins of cardiac insufficiency: a case of iliac arteriovenous fistula post-spinal disc surgery

In this case report, we present the unique and intriguing case of a 57-year-old man who experienced exertional palpitations and shortness of breath for 5 years. He was diagnosed with idiopathic heart failure three years ago, leading to diuretic treatment. Physical examination revealed notable left lower extremity swelling, severe varicose veins, and cardiac murmurs. Echocardiography showed significant cardiac enlargement and severe functional mitral and tricuspid valve regurgitation. Computed tomography (CT) imaging uncovered a 10 mm left common iliac arteriovenous fistula, causing abnormal early filling of the inferior vena cava (IVC) and marked IVC dilation. Open surgical repair of the arteriovenous fistula resulted in symptom relief and improved cardiac function. This case underscores the importance of considering unusual causes in heart failure patients and highlights the value of early diagnosis and intervention in complex cardiac-vascular interactions.

Aggravated Cardiac Remodeling post Aortocaval Fistula in Unilateral Nephrectomized Rats.

BackgroundAortocaval fistula (AV) in rat is a unique model of volume-overload congestive heart failure and cardiac hypertrophy. Living donor kidney transplantation is regarded as beneficial to allograft recipients and not particularly detrimental to the donors. Impact of AV on animals with mild renal dysfunction is not fully understood. In this study, we explored the effects of AV in unilateral nephrectomized (UNX) rats.MethodsAdult male Sprague-Dawley (SD) rats were divided into Sham (n = 10), UNX (right kidney remove, n = 10), AV (AV established between the levels of renal arteries and iliac bifurcation, n = 18) and UNX+AV (AV at one week after UNX, n = 22), respectively. Renal outcome was measured by glomerular filtration rate, effective renal plasma flow, fractional excretion of sodium, albuminuria, plasma creatinine, and cystatin C. Focal glomerulosclerosis (FGS) incidence was evaluated by renal histology. Cardiac function was measured by echocardiography and hemodynamic measurements.ResultsUNX alone induced compensatory left kidney enlargement, increased plasma creatinine and cystatin C levels, and slightly reduced glomerular filtration rate and increased FGS. AV induced significant cardiac enlargement and hypertrophy and reduced cardiac function and increased FGS, these changes were aggravated in UNX+AV rats.ConclusionsAlthough UNX only induces minor renal dysfunction, additional chronic volume overload placement during the adaptation phase of the remaining kidney is associated with aggravated cardiac dysfunction and remodeling in UNX rats, suggesting special medical care is required for UNX or congenital monokidney subjects in case of chronic volume overload as in the case of pregnancy and hyperthyroidism to prevent further adverse cardiorenal events in these individuals.

Can intensive exercise harm the heart? You can get too much of a good thing.

Can intensive exercise harm the heart? You can get too much of a good thing.

Targeted GLUT-4 deficiency in the heart induces cardiomyocyte hypertrophy and impaired contractility linked with Ca2+ and proton flux dysregulation

There is clinical evidence to suggest that impaired myocardial glucose uptake contributes to the pathogenesis of hypertrophic, insulin-resistant cardiomyopathy. The goal of this study was to determine whether cardiac deficiency of the insulin-sensitive glucose transporter, GLUT4, has deleterious effect on cardiomyocyte excitation–contraction coupling. Cre-Lox mouse models of cardiac GLUT4 knockdown (KD, 85% reduction) and knockout (KO, >95% reduction), which exhibit similar systemic hyperinsulinemic and hyperglycemic states, were investigated. The Ca2+ current (ICa) and Na+–Ca2+ exchanger (NCX) fluxes, Na+–H+ exchanger (NHE) activity, and contractile performance of GLUT4-deficient myocytes was examined using whole-cell patch-clamp, epifluorescence, and imaging techniques. GLUT4-KO exhibited significant cardiac enlargement characterized by cardiomyocyte hypertrophy (40% increase in cell area) and fibrosis. GLUT4-KO myocyte contractility was significantly diminished, with reduced mean maximum shortening (5.0±0.4% vs. 6.2±0.6%, 5 Hz). Maximal rates of shortening and relaxation were also reduced (20–25%), and latency was delayed. In GLUT4-KO myocytes, the ICa density was decreased (−2.80±0.29 vs. −5.30±0.70 pA/pF), and mean INCX was significantly increased in both outward (by 60%) and inward (by 100%) directions. GLUT4-KO expression levels of SERCA2 and RyR2 were reduced by approximately 50%. NHE-mediated H+ flux in response to NH4Cl acid loading was markedly elevated GLUT4-KO myocytes, associated with doubled expression of NHE1. These findings demonstrate that, independent of systemic endocrinological disturbance, cardiac GLUT4 deficiency per se provides a lesion sufficient to induce profound alterations in cardiomyocyte Ca2+ and pH homeostasis. Our investigation identifies the cardiac GLUT4 as a potential primary molecular therapeutic target in ameliorating the functional deficits associated with insulin-resistant cardiomyopathy.

Changes over time in echocardiographic measurements in young Standardbred racehorses undergoing training and racing and association with racing performance

To evaluate changes over time in echocardiographic measurements in young Standardbred racehorses undergoing training and racing and determine whether there was any relationship between cardiac dimensions and racing performance. Longitudinal observational study. 103 horses. 2-dimensional and M-mode echocardiography was performed 4 times at 6-month intervals. Significant cardiac enlargement took place during the study period as indicated by increases in left ventricular internal diameter in diastole (LVIDd), estimated left ventricular muscle mass (LV mass), and mean wall thickness attributable to eccentric left ventricular hypertrophy. Estimated body weight was positively correlated with left ventricular size, and males had significantly larger LVIDd and LV mass than did females. Horses that were racing regularly had larger LVIDd and LV mass than did unraced horses. A significant relationship between left ventricular size and racing performance was observed. The relationship was strongest at the time of the fourth examination. Results suggest that age must be taken into account when interpreting results of echocardiography in young Standardbred racehorses because significant cardiac enlargement takes place with age and training. A larger heart was found in horses that were racing, and size of the heart was correlated with athletic performance of the horse.

M-mode, cross-sectional and color flow Doppler echocardiographic findings in acute rheumatic fever

AbstractM-mode, cross-sectional and color flow Doppler echocardiography were performed in 28 patients with acute rheumatic fever. The patients were grouped according to the presence or absence of carditis and congestive heart failure. Abnormal echocardiographic findings were found in 25 patients (89%), including five with no carditis. M mode echocardiography showed significant cardiac enlargement in all patients with carditis, and in two patients with no carditis. The myocardial contractility, as based on ejection fraction and fractional shortening, was normal in all patients except one. Prolapse of the leaflets of the mitral valve (57%) and increased echogenicity of the leaflets of the mitral valve (36%) were the most common findings seen on cross-sectional echocardiography. Pericardial effusion was seen in six patients (21%), all with heart failure. Color flow and Doppler echocardiography showed that mitral regurgitation, which was seen in 24 patients (86%), was the most common finding. Aortic regurgitation was found in 17 patients (60%). The presence of congestive heart failure in patients with carditis was related to the severity of the valvar regurgitation and the number of valves involved. Echocardiographic evidence of rheumatic involvement of the heart may be observed even in the absence of clinical signs of carditis.

Temporal relationships of treatment with angiotensin converting enzyme inhibitors on the hypertension and cardiac hypertrophy in spontaneously hypertensive rats.

Two groups of spontaneously hypertensive rats (SHRs) were treated with captopril and enalapril, respectively. Treatment was started at weaning and at 8 months of age. Blood pressure was maintained close to normal in rats treated from weaning and significantly lowered but not to normal levels in rats started on treatment at 8 months. The long-term treated rats did not show significant cardiac enlargement whereas those treated at 8 months had an increase in cardiac size although not to the same level as untreated animals. Treatment with minoxidil and minoxidil plus propranolol similarly lowers blood pressure, but does not reduce myocardial hypertrophy. The data confirm that both the time of onset of treatment as well as the type of drug influence the myocardial complications of hypertension in SHRs. These studies further demonstrate the use of the SHR as a model for clinical pharmacologic studies with antihypertensive agents.

Chronic exercise and left ventricular structure and function in healthy human subjects

Twelve healthy well-trained participants in a supervised exercise program (mean age, 41.3 yr) were compared with 12 sedentary control subjects (mean age, 38.9 yr) with physical characteristics similar to the exercised group (EG) before training. Resting echocardiograms revealed significantly lower heart rates (HR) in the EG compared with control group (CG) but no evidence for cardiac structural differences between groups. Radionuclide angiograms performed at rest and during two levels of supine cycling (HR targets: 120 and 140 beats X min-1) resulted in increases in background-corrected end-diastolic counts [EDC(bc)] and confirmed use of the Frank-Starling mechanism in the majority of subjects. Mean values (+/- SD) for ejection fraction (EF) and normalized peak systolic ejection rate (PSER) (P greater than 0.05 between groups) were the following. (Formula: see text) The results suggested that fitness training does not induce significant cardiac enlargement as apparent from measurements at rest or important changes in contractile state during exercise. Increases in exercise stroke volume with such training may be the result of an increased end-diastolic volume.

Myocardial protein kinases: II. Isoproterenol-induced changes in the activity of soluble and membrane-bound enzymes of rat left ventricle

Isoproterenol treatment, which produced significant cardiac enlargement at 12 h, also resulted in significant changes ( P < 0.05) in the activities of both the soluble and membrane-bound protein kinases of left ventricle. The observed changes fell into two categories: (1) Effects on holoenzyme levels—a significant decrease in the amount of soluble holoenzyme at 10 min was followed by a concomitant increase in the amount of membrane-bound holoenzyme at 30 min, suggesting that the soluble holoenzyme may have been translocating to particulate acceptor sites. (2) Effects on catalytic subunits—the activity of the membrane-bound catalytic subunit, which was shown to vary directly with ATP levels, increased significantly at 20 min and remained elevated for 8 h (phase 1). Between 8 and 24 h, its activity decreased to a minimum value (phase 2). During these two phases, the activity of the soluble catalytic subunit varied inversely with that of the membrane-bound protein kinase. Changes due to repeated doses of isoproterenol (1–14 days) also were examined in the soluble fraction. The activity of soluble protein kinase was found to return to control values between 2 and 10 days, when the growth rate of enlarged hearts became parallel with that of normal controls. Data indicate that isoproterenol-induced changes in the location of the holoenzymes and in the activity of membrane-bound catalytic subunit become apparent well in advance of significant increase in heart weight and therefore might play a role in the sequence of events leading to cardiac hypertrophy.

Amyloid in the aged heart: frequency and clinical significance.

Cardiac amyloid accumulation is a common autopsy finding in elderly persons, the frequency increasing with each advancing age decade. In most cases the deposits are microscopic, confined to the atrial subendocardium, and of dubious significance. In a few cases, however, there is much more extensive cardiac involvement, with infiltration of the ventricular musculature and intracardiac conduction system. In the authors' recent autopsy study of 100 patients over 60 years of age, 10 had diffuse cardiac amyloidosis with biventricular involvement. Microscopically, the amyloid deposits often resembled foci of interstitial fibrosis. Significant cardiac enlargement (weight greater than 380 gm) was present in only 2 of these patients, and in only one of them were the clinical signs and symptoms clearly attributable attributable to the amyloid infiltration. It was difficult to assess the possible contribution of ventricular amyloid to congestive failure since most of the patients also had coronary arteriosclerosis. In the aged, clinically significant cardiac amyloidosis associated with cardiac enlargement appears to be part of a disease spectrum more commonly characterized by focal, clinically insignificant cardiac amyloid deposits. Yet several features suggest that senile cardiac amyloidosis may differ from the clinically significant cardiac amyloidosis occassionally seen in younger patients.

Roentgenographic features of thymolipoma.

1. The thymolipoma usually begins in young individuals and, being virtually asymptomatic, may attain huge proportions before discovery.2. The smaller lesions cannot be distinguished roentgenographically from other benign anterior mediastinal masses.3. The large tumors tend to slump toward the diaphragms, leaving the anterior superior mediastinal space lucent, an unusual finding in the majority of large mediastinal tumors. Often the large mass simulates cardiomegaly, but a normal position of the esophagus on the lateral roentgenogram is evidence against significant cardiac enlargement.4. Well penetrated chest roentgenograms will usually demonstrate the outlines of the underlying heart and diaphragms, since these structures are always of greater roentgenographic density than the fatty tumor. This finding is virtually pathognomonic and will obviate the need for angiocardiography or pneumomediastinum.5. The thin periphery of the tumor may be considerably more lucent than the bulky center—a suggestive finding.

The prognosis of acute rheumatic fever

The clinical events of acute rheumatic fever have been correlated with the subsequent cardiac sequelae in 441 children and adolescents who were receiving continuous antimicrobial prophylaxis after rheumatic episodes that occurred during 1950–1957. The follow-up examinations, which extended for a mean of 7.8 years, were performed at monthly or bimonthly intervals in an outpatient epidemiologic research clinic, where special methods were used to improve the objectivity, precision, and standardization of the examining physicians' cardiac auscultation and roentgenographic interpretation. “Carditis” was defined clinically according to the presence or absence of significant cardiac murmurs, specified by rigorous criteria; “severe carditis” was manifested by significant cardiac enlargement or decompensation. The long-term results showed the following: 1. 1. The proportionate distribution and severity of carditic and noncarditic clinical features in the population was similar to that of a comparable population whose acute rheumatic episodes occurred during 1958–1960. 2. 2. All of the 181 patients who were initially free of carditis have remained free of rheumatic heart disease. 3. 3. Of the 260 patients with various forms of carditis initially, the evidence of cardiac damage has disappeared in 113, leaving only 147 patients with definite residual rheumatic heart disease. 4. 4. Of those 147 patients, 12 have died. All but one of these 12 patients had severe carditis in the antecedent acute rheumatic episode, and only one had later evidence of recurrent or persistent acute rheumatic inflammation. 5. 5. The disappearance of rheumatic heart disease was most likely to occur in patients who had: mild rather than severe carditis; a first rheumatic attack rather than a recurrence; systolic murmurs only rather than diastolic murmurs; murmurs of one valve rather than of two; and arthropathic manifestations rather than no joint symptoms. 6. 6. In the 271 patients whose acute rheumatic episodes were first attacks, the cardiac outcome depended on the presence and severity of carditis when treatment began, and was unrelated to the agent of treatment or to the promptness with which treatment was started after the onset of symptoms. 7. 7. Evidence of pericarditis was most common in patients with other manifestations of carditis and did not alone appear to influence prognosis. 8. 8. A prolonged P-R electrocardiographic interval occurred in about one third of all patients during the acute rheumatic episodes, regardless of the simultaneous presence or severity of carditis, and had no direct relationship to the ultimate cardiac state. These results confirm certain well-established concepts of clinical behavior in acute rheumatic fever, and contradict others. They indicate the importance of careful attention to clinical observation in recognizing the different subgroups of patients, with different cardiac prognosis, who constitute the complex, diverse spectrum of acute rheumatic fever.

冠状動脈疾患に関する研究(第1報) : 冠状動脈疾患に関する集団検診とその予後について

The mass survey on coronary artery disease (CAD) was perfomed during the period of 1956 to 1958 in Tokyo. This study was concerned with the incidence and grade of CAD in four male populations aged above 40, and the methods of laboratory examination and the criteria of clinical diagnosis of CAD were also discussed.Inquiry of detailed medical history and physical examination including blood pressure measurement were carried out by physician. In addition, height and Weight were measured, and ECG and chest X-ray film were examined.Total number studied at initial examination was 1122 cases which were classified into four populations, namely, officers, clerks, professors and medical practitioners.Of these cases, 487 were reexamined in 1 to 2 years follow-up period.The classification of CAD was based upon the criteaia shown below : GROUR I : Infarction.GROUP A : 1) Coronary T 2) Positive exercise test 3) Abnormal S-T deviation (over 0.05 mV.) with B. P. under 179/99 mmHg.GROUP B : Abnormal ST-T deviation and/or significant cardiac enlargement with B. P. over 180/100 mmHg.GROUP C : 1) Low voltage 2) Prolongation of PQ interval (over 0.20") 3) Bundle-branch block 4) Prolongation of QRS complex (over 0.01") 5) Abnormal ST-T deviation (under 0.05 mV.) with B. P. under 179/99mmHg. 6) Significant cardiac enlargement with B. P. under 179/99 mmHg. 7) Arrhythmia beginning after middle age.GROUP D* : Hypertension (over 160/90 mmHg.) without electrocardiographic. and roentgenologic abnormalities GROUP E* : No abnormalities.(*Group D and E are not CAD.)1) In 32.8 per cent of all cases, hypertension over 160/90 mmHg. was found, and prevalence rate of hypertension showed a positive correlation with age and relative weight. But there were no differences in prevalence of hypertension between four populations.2) There were no cases with myocardial infarction, but group A was found in 2 to 3 per cent, group B in 9.3 per cent and group C in 24.8 per cent of apparently healthy indiviauals.3) Diagnosis of group A was made in 1.0 per cent of cases aged 40 to 49 years, in 3.8 per cent of 50 to 59, in 7.7 per cent of above 60. The prevalence rate of CAD was increased with age.4) The prevalence of CAD was higher in cases with high levels of blood pressure and/or relative weight than those with normal or low levels.5) Significant relationship of CAD to diet, smoking and alcohol intake was not demonstrated.6) The incidence of myocardial infarction or sudden death among 487 cases, which were reexamined at 1 to 2 years' follow-up survey, was 0.4 per cent (2 cases) and that of group A was 1.0 per cent (5 cases). All these cases showed some abnormal findings at the initial examination.7) In 1 to 2 years' follow-up period, no incidence of myocardial infarction or angina pectoris was seen in the group which was diagnosed as group A, suggesting the necessity of health control by mass survey.

LIMITED USE OF ANTICOAGULANTS IN ACUTE MYOCARDIAL INFARCTION

• Patients with the diagnosis of acute myocardial infarction can be classified as good or poor risks at the time of the first examination. Those who have never had previous infarctions, who do not have intractable pain, extreme or persistent shock, significant cardiac enlargement, gallop rhythm, congestive heart failure, auricular fibrillation or flutter, or ventricular tachycardia or intraventricular block, and who do not have diabetic acidosis or other states predisposing to thrombosis are classified as good risks. Data previously reported are here supplemented by data from 511 good-risk patients who did not receive anticoagulant therapy and were closely watched for thromboembolic complications. The latter occurred in only 3.7% of the cases and all were of a mild nature. There were 18 deaths. Analysis of the causes of death did not yield evidence that anticoagulant therapy would have reduced the mortality to a significant degree. The mortality of 3.5% for the good-risk patients was in marked contrast to the mortality of 60% previously found for poor-risk patients. The authors believe that anticoagulant therapy, which has certain hazards, is neither necessary nor desirable for patients who have been classified as good risks by the above criteria.