Smaller Cardiac Size Research Articles

Impact of cardiac size on diagnostic performance of single-photon emission computed tomography myocardial perfusion imaging: insights from the REgistry of Fast Myocardial Perfusion Imaging with NExt generation single-photon emission computed tomography.

Variation in diagnostic performance of single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) has been observed, yet the impact of cardiac size has not been well characterized. We assessed whether low left ventricular volume influences SPECT MPI's ability to detect obstructive coronary artery disease (CAD) and its interaction with age and sex. A total of 2066 patients without known CAD (67% male, 64.7 ± 11.2 years) across nine institutions underwent SPECT MPI with solid-state scanners followed by coronary angiography as part of the REgistry of Fast Myocardial Perfusion Imaging with NExt Generation SPECT. Area under receiver-operating characteristic curve (AUC) analyses evaluated the performance of quantitative and visual assessments according to cardiac size [end-diastolic volume (EDV); <20th vs. ≥20th population or sex-specific percentiles], age (<75 vs. ≥75 years), and sex. Significantly decreased performance was observed in patients with low EDV compared with those without (AUC: population 0.72 vs. 0.78, P = 0.03; sex-specific 0.72 vs. 0.79, P = 0.01) and elderly patients compared with younger patients (AUC 0.72 vs. 0.78, P = 0.03), whereas males and females demonstrated similar AUC (0.77 vs. 0.76, P = 0.67). The reduction in accuracy attributed to lower volumes was primarily observed in males (sex-specific threshold: EDV 0.69 vs. 0.79, P = 0.01). Accordingly, a significant decrease in AUC, sensitivity, specificity, and negative predictive value for quantitative and visual assessments was noted in patients with at least two characteristics of low EDV, elderly age, or male sex. Detection of CAD with SPECT MPI is negatively impacted by small cardiac size, most notably in elderly and male patients.

Abstract P067: Elite Female Athlete’S Heart Of Asians: The Chief Heart Study

Background: Women have been reported with smaller cardiac size and blood volume in response to intensive physical training compared to men. However, adaptive cardiac characteristics to exercises have been rarely compared between elite and non-elite female athletes particularly among Asian athletes. Methods: This study included 177 women, aged 18-34 years, under a standard 6-month military training course in Taiwan. In 2020, all attended a 3000-meter run to assess endurance capacity, and 89 were randomly selected to complete a 2-minute push-up test to assess muscular strength. Elite athletes were those whose performance fell one standard deviation above the mean (16%) of each exercise modality. Cardiac characteristics evaluated by a 12-lead electro-cardiography (ECG) and transthoracic echocardiography were compared between elite and non-elite female athletes. Multiple logistic regression analysis was used to determine the predictors of elite female athletes’s cardiac adaptation to endurance versus strength exercise. Results: Compared to non-elite controls, elite female endurance athletes had greater QRS duration (92.12±10.35 ms vs. 87.26±9.89 ms, p =0.01) and higher prevalence of right axis deviation (34.9% vs. 11.1%, p &lt;0.001). There were no differences in any echocardiographic variables, i.e. left ventricular mass index and diastolic function. Greater QRS duration, right axis deviation and lower systolic blood pressure levels were independent predictors of elite endurance athletes [odds ratios (OR) and 95% confidence intervals: 1.05 (1.01-1.09), 2.91 (1.12-7.59) and 0.93 (0.88-0.98), respectively]. In contrast, elite female strength athletes had greater right ventricular outflow tract (RVOT) (28.06±3.57 mm vs. 25.38± 3.61 mm, p =0.007), while demonstrated no differences in ECG variables. Greater RVOT was the only predictor of elite strength athletes [OR: 1.26 (1.05-1.50)]. Conclusions: In physically active Asian women, QRS prolongation and right axis deviation in ECG rather than the heart structure and functional changes characterize the elite endurance athletes. However, the right ventricular outflow enlargement documented in elite strength athletes requires further investigations.

Factors associated with abnormal left ventricular ejection fraction (decreased or increased) in patients with sepsis in the intensive care unit

Sepsis-induced cardiomyopathy (SIC) is known to show cardiac dysfunction in patients with sepsis. Both a decrease or an increase in ejection fraction (EF), an indicator of cardiac function, can occur. The purpose of this study was to identify factors associated with abnormal left ventricular (LV) function measured by EF in patients with sepsis in the intensive care unit (ICU). This was a retrospective study performed from November 2016 to December 2018. Three-hundred and sixty-six patients (mean age, 73 ± 13 years; 191 [52%] men) admitted to the ICU with sepsis were included. Patients were classified into three categories according to LV EF (group 1 -[EF<50%, n = 36], group 2 -[50≤EF<70%, n = 252], and group 3 -[EF≥70%, n = 78]). Echocardiographic assessment was performed within 48 hours of diagnosis of sepsis. We analyzed clinical factors including mortality, echocardiographic findings, and laboratory parameters. Decreased LV EF occurred in 36 (10%) patients and hyper-dynamic EF developed in 78 (21%) patients. Of 366 patients, 103 (28%) patients died. Baseline characteristics were similar in the three groups, except female sex an indicator of abnormal EF. Mortality rates were also similar in the three groups; however, mortality rates were significantly higher in patients with abnormal EF (decreased or increased vs. normal). Echocardiographic parameters were significantly different in the three groups, in terms of LV systolic parameters and chamber size. Small left atrium (LA) and small LV were significantly associated with abnormal EF (especially in patients with increased EF). High brain natriuretic peptide was associated with decreased EF. Among these factors, female sex and small LA were significantly associated with abnormal EF in the multiple regression analysis. Our findings highlight that female sex and small cardiac size are associated with abnormal EF, and therefore, death. Therefore, female patients and patients with small LA should be monitored closely when they present with sepsis.

Global longitudinal strain: is it a superior assessment method for left ventricular function in patients with chronic mitral regurgitation undergoing mitral valve replacement?

Left ventricular ejection fraction may remain normal or even higher despite significant impairment of contractility in cases of mitral regurgitation. The aim of this study is to evaluate the changes in left ventricular function after mitral valve replacement and to study the role of global longitudinal strain in detecting early left ventricular dysfunction using speckle tracking. Study involved 31 patients who underwent mitral valve replacement for mitral regurgitation. Patient's preoperative and postoperative echocardiography (conventional parameters and global longitudinal strain) and other parameters like functional status, radiological findings, and electrocardiogram were recorded to evaluate left ventricular function. All patients presented in advanced stage with New York heart association class III (67.7%) and IV (32.3%). There was significant decline in left ventricular ejection fraction (with the mean value from 64.58 to 40.13%) and global longitudinal strain (- 15.57 ± 4.98to - 8.97) in the immediate postoperative period (~ 7days). However, there was a rise in both left ventricular ejection fraction (mean 52.48%) and in global longitudinal strain (mean - 14.44 ± 3.67) at 3months. Left ventricular and atrial size decreased significantly immediately after surgery, which further declined at 3months. We also found that patients who attained a left ventricular ejection fraction of > 50% in postoperative period had better left ventricular ejection fraction and global longitudinal strain preoperatively. In addition, they had smaller cardiac size and milder pulmonary hypertension comparatively. Mitral valve replacement in mitral regurgitation results in decline in left ventricular function immediately after surgery. In patients with chronic mitral regurgitation, left ventricular ejection fraction is fallacious and global longitudinal strain can be an important tool to assess left ventricular ejection fraction.

Cardio-Thoracic Ratio Evaluation of Cardiac Sihlouette Compared with the Vertebral Heart Scale in Cats

The aim of the study was to compare the VHS with CTR and to asses the discrimination potential of CTR between normal heart size and microcardia or cardiomegaly in cats. The study included 125 cats, 68 females and 57 males with age between 1 and 17 years. The patiens were distributed in 3 groups based on VHS: Group A (n=31) cats with small cardiac size (microcardia), Group B (n=51) cats with normal cardiac size and Group C (n=43) cats with heart enlargement (cardiomegaly). There was a good correlation between VHS and CTR for the entire studied group (r 2 =0.516, p<0.01). There was a statistically significant correlation between VHS and CTR in normal heart size and cardiomegaly groups (r 2 =0.383; p<0.01), (r 2 =0.339,p<0.05). There was a poor correlation between VHS and CTR in microcardia ( r 2 =0.164;p=0.378). There was statistically diference between microcardia group and normal cardiac size group (p<0.05) and also between cardiomegaly and normal cardiac size groups (p<0.01). Cardio-thoracic ratio is a valid method being well correlated with VHS. The CTR measurement can be used for assessing cardiac size in cats and can discriminate between normal heart size and microcardia or cardiomegaly.

High-frequency speckle tracking echocardiography in the assessment of left ventricular function and remodeling after murine myocardial infarction

The objectives of this study were to assess the feasibility and accuracy of high-frequency speckle tracking echocardiography (STE) in a murine model of myocardial infarction (MI). STE is used clinically to quantify global and regional cardiac function, but its application in mice is challenging because of the small cardiac size and rapid heart rates. A high-frequency micro-ultrasound system with STE (Visualsonics Vevo 2100) was compared against magnetic resonance imaging (MRI) for the assessment of global left ventricular (LV) size and function after murine MI. Animals subjected to coronary ligation (n = 46) or sham ligation (n = 27) were studied 4 wk postoperatively. Regional and global deformation were also assessed. STE-derived LV ejection fraction (EF) and mass correlated well with MRI indexes (r = 0.93, 0.77, respectively; P < 0.001), as did STE-derived mass with postmortem values (r = 0.80, P < 0.001). Higher STE-derived volumes correlated positively with MRI-derived infarct size (P < 0.01). Global strain parameters were significantly reduced after MI (all P < 0.001) and strongly correlated with LV mass and MRI-derived infarct size as promising surrogates for the extent of remodeling and infarction, respectively (both P < 0.05). Regional strain analyses showed that radial strain and strain rate were relatively preserved in anterior basal segments after MI compared with more apical segments (P < 0.001); however, longitudinal strain and strain rate were significantly impaired both basally and distally (P < 0.001). Strain-derived parameters of dyssynchrony were significantly increased in the MI group (P < 0.01). Analysis time for STE was 210 ± 45 s with acceptable inter- and intraobserver variability. In conclusion, high-frequency STE enables quantitative assessment of regional and global function in the remodeling murine LV after MI.

Evaluation of left ventricular volumes in the early neonatal period using three-dimensional echocardiography

Awareness about normal cardiac volumes in the neonatal period is very important for understanding the cardiac function; however, the small cardiac size of neonates makes it difficult to perform invasive examinations. Three-dimensional echocardiography is used to evaluate cardiac volumes in children. However, no studies using this method have examined left ventricular volumes in neonates during the early neonatal period. The study group consisted of 255 normal neonates. Comparisons of the stroke volume calculated according to the velocity-time integral and Pombo method were made. The volumes in both end-diastole and end-systole and the stroke volume gradually decreased over time after birth. Participants with continuous a persistent ductus arteriosus flow had higher stroke volumes than those without persistent ductus arteriosus. The average end-diastolic volume per body surface area (m2) was 30.61 ml/m2 in boys and 29.80 ml/m2 in girls, whereas the ventricular end-systolic volume was 12.89 ml/m2 in boys and 12.80 ml/m2 in girls among the participants without persistent ductus arteriosus. The average stroke volume was 17.70 ml/m2 in boys and 17.00 ml/m2 in girls. Statistically significant gender differences were observed in the end-diastolic volume (p = 0.0053), stroke volume (p < 0.0001), and ejection fraction (p = 0.039). The cardiac index was calculated to be 2.04 L/minute/m2 in boys and 1.95 L/minute/m2 in girls, which was significantly lower than that calculated using the velocity-time integral and Pombo method (p < 0.0001). Significant gender differences in the end-diastolic volume, stroke volume, and ejection fraction at birth were revealed. The cardiac index in the early neonatal period was found to be relatively smaller than what had previously been recognised.

Hemodynamic characteristics in chronic obstructive lung disease as related to cardiac size.

The hemodynamic adaptation during exercise was evaluated in 19 patients suffering from chronic obstructive lung disease. They were divided into two groups according to cardiac size on the X-ray (group 1, small; group 2, normal). A small cardio-thoracic ratio could be correlated with 'emphysema' assessed on the basis of hyperinflation and a low transfer test for CO. No clear-cut difference could be found between the two groups concerning the hemodynamic data at rest or during exercise. However, for all subjects, the cardiac output was found to be slightly related to the cardiac size (smaller cardiac output for smaller cardiac size). During exercise, a low cardiac output was characterized by a low oxygen transport and a high level of lactate. From this, it is suggested that a small cardiac size, a classical feature of hyperinflation and emphysema, may lead to a low cardiac output. The explanation for these results is speculative, but variable hemodynamic profiles in chronic obstructive lung disease with or without hyperinflation may be related to the morphology of the cardiac chambers and to variable intrathoracic pressure regimes during respiration.

Studies of the Circulation and Respiration in a Patient with Anasarca Following Administration of Cortin and Sodium Chloride

Edema is of common occurrence in patients with Addison's disease following treatment with desoxycorticosterone and sodium chioride (1 4). In addition to edema, some patients also exhibit dyspnea, reduced vital capacity, elevated venous pressure and roentgenographic changes suggestive of cardiac dilatation. It has been assumed that heart failure occurs under these circumstances, as a consequence of cardiac dilatation due to overloading the circulation with fluid. However, all of the patients thus far described had the decreased blood volume and abnormally small cardiac size found in Addison's disease. The present report is based on studies made in a patient without Addison's disease who developed massive generalized edema following administration of cortin and sodium chloride. REPORT OF CASE B. F. (B. I. H. #52040), a 43-year-old man, with a past history of asthma, eczema and eosinophilia for many years and no evidence of adrenal cortical insufficiency, entered the hospital on Jan. 10, 1942, because of dyspnea and generalized edema.