Effect of food intake on myocardial performance index

Effect of food intake on echocardiographic measurements in healthy elderly

OBJECTIVE

This study evaluates whether food intake affects systolic and diastolic echocardiographic measurements in healthy seniors.

METHODS

Thirty healthy subjects 65-70 years of age were investigated with echocardiography, at fasting and then 30, 90, and 180 min after a meal.

RESULTS

After 30 min the biggest changes were seen in left ventricular wall stress and myocardial performance index with a decrease of 45% and 33%, respectively, compared to fasting values. Significant (p < .05) increases also were seen in left ventricular stroke volume, left ventricular cardiac output, left ventricular cardiac index, left ventricular outflow velocity-time integral, peak of early diastolic (E) and late diastolic (A) mitral flow velocities, the E/A ratio, pulsed tissue Doppler peak systolic (s') and early (e') and late (a') diastolic velocities, pulmonary vein peak velocities in systole (S) and diastole (D), mitral annular plane systolic excursion (MAPSE), tricuspid annular plane systolic excursion (TAPSE), and global longitudinal strain (GLS) (increases ranging 6%-19%). After 90 min there remained a decrease in wall stress and myocardial performance index of 31% and 17%, respectively, and smaller, but still significant, changes could be seen in left ventricular stroke volume, left ventricular outflow velocity-time integral, MAPSE (lateral), TAPSE, GLS, and a few pulsed tissue Doppler peak systolic velocities and late diastolic velocities. An increase also could be seen in deceleration time of E-wave (DT). After 180 min, all variables except DT were back at baseline or below. No significant changes were seen in S/D ratio, lateral early diastolic velocity (e' lateral) and E/e'ratio.

CONCLUSIONS

This study shows that food intake affects commonly used echocardiographic parameters, both systolic and diastolic, in healthy seniors. With a few exceptions, the changes seen in the older population were less pronounced than previous studies in younger subjects.

Acute Echocardiographic Effects of Exogenous Ketone Administration in Healthy Participants

BACKGROUND

Interest in therapeutic applications of exogenous ketones has grown significantly, spanning patients with heart failure to endurance athletes. Exogenous ketones engender significant effects on cardiac function in heart failure and provide an ergogenic benefit in athletes. The aim of this study was to assess the effects of exogenous ketones on cardiac function in healthy participants.

METHODS

In a single-arm intervention study, 20 fasting, healthy participants underwent comprehensive echocardiography (two-dimensional, Doppler, and strain) before and 30 min after weight-based oral ketone ester administration. The relationship between changes in log-transformed biomarker levels and change in absolute global longitudinal strain (GLS) was assessed using linear regression.

RESULTS

The mean age was 30 ± 7 years, 50% were women, 45% were nonwhite, and the average body mass index was 24.3 ± 3.1 kg/m². Ketone ingestion acutely elevated β-hydroxybutyrate levels from a median of 0.13 mmol/L (interquartile range, 0.10-0.37 mmol/L) to 3.23 mmol/L (interquartile range, 2.40-4.97 mmol/L) (P < .001). After ketone ester consumption, systolic blood pressure, heart rate, biventricular function, left ventricular GLS, and left atrial (LA) strain all augmented, while systemic vascular resistance decreased. Displayed as mean change, increases in ejection fraction (3.1%; 95% CI, 2.0%-4.2%; P < .001), GLS (2.0%; 95% CI, 1.4%-2.7%; P < .001), right ventricular S' (1.1 cm/sec; 95% CI, 0.4-1.8 cm/sec; P = .004), LA reservoir strain (7%; 95% CI, 3%-12%; P = .005), and LA contractile strain (4%; 2%-6%; P = .001) were observed. During robustly achieved ketosis, change in GLS was inversely associated with change in nonesterified fatty acids (P = .019).

CONCLUSIONS

In a single-arm study, systolic blood pressure, heart rate, biventricular function, and LV and LA strain acutely augmented after ketone ester ingestion in healthy, fasting participants, similar to several effects observed in the failing heart. These data may provide supporting data for the ergogenic benefits observed in athletes and may become increasingly relevant with exogenous ketone consumption across a variety of cardiovascular and noncardiovascular applications.

Myocardial performance index is associated with cardiac computed tomography findings in patients with suspected coronary artery disease

BACKGROUND

Studies suggest cardiac time intervals to be associated with cardiac ischemia. A novel method to assess cardiac time intervals by tissue Doppler echocardiography has been proposed. Cardiac time intervals can assess the myocardial performance index (MPI), which quantifies the proportion of time spent contributing effective myocardial work. We hypothesized that MPI associates with coronary artery lesions detected by cardiac computed tomography (CT) in patients suspected of coronary artery disease (CAD).

METHODS

We investigated patients referred for cardiac CT under suspicion of CAD who had an echocardiogram performed. Curved m-mode tissue Doppler imaging was used to measure cardiac time intervals and MPI. The outcome was coronary artery lesions, defined as a calcium score > 400 and/or coronary artery stenosis (>70% luminal narrowing). Logistic regression was applied with multivariable models including: (a) SCORE chart risk factors and (b) SCORE chart risk factors, body mass index, dyslipidemia, familial history of CAD, diabetes mellitus, LVEF, and left ventricular mass index.

RESULTS

Of 404 patients, 41 (10%) had a coronary artery lesion. Overall, 42% were male, mean age was 58 years, and LVEF was 58%. Patients with coronary artery lesions exhibited higher MPI than those without (0.52 vs. 0.44, P < .001). MPI associated with coronary artery lesions in unadjusted analyses (OR = 1.69 [1.30-2.19], per 0.1 increase), and this association persisted when adjusted for SCORE chart risk factors (OR = 1.55 [1.16-2.07], P = .003, per 0.1 increase), and additional risk factors (OR = 1.64 [1.11-2.41], P = .013, per 0.1 increase).

CONCLUSION

Curved m-mode-derived MPI is associated with coronary artery lesions detected by cardiac CT in suspected CAD patients.