Isometric Handgrip Echocardiography is a More Powerful Diastolic Discriminator than Conventional Cycle Echocardiography

Cycle echocardiography is currently recommended for assessing cardiac involvement (i.e. left ventricular diastolic dysfunction) in patients with unexplained dyspnea on exertion. However, cycle echocardiography is often limited by movement and respiratory artifact, particularly in obese patients with dyspnea. Our group has recently shown that isometric handgrip echocardiography is a powerful diastolic discriminator, capable of unmasking subclinical stress induced diastolic dysfunction. How isometric handgrip echocardiography compares to conventional cycle echocardiography however, remains unclear and was the focus of the present investigation. We hypothesized that isometric handgrip echocardiography would unmask more diastolic dysfunction, given its markedly different hemodynamic load compared to cycle echocardiography. To test this hypothesis, we recruited 24 individuals from the community (9 male, 15 female, age range: 18 – 80), who all performed 3 minutes of isometric handgrip echocardiography followed by 3 minutes of dynamic cycle exercise (20 W). At rest and during the final minute of each exercise protocol heart rate (HR), mean arterial pressure (MAP) and Doppler derived E/e′ were recorded. Consistent with our previous work, and that of others, responders were defined as ΔE/e′ > 1.5 while non‐responders were defined as ΔE/e′ < 1.5. Both isometric handgrip and low‐intensity cycle exercise resulted in a similar rise in HR (ΔHR: 22 ± 13 vs . 25 ± 7, handgrip vs . cycle exercise, P > 0.05), while isometric handgrip resulted in a larger increase in MAP (ΔMAP: 28 ± 14 vs . 16 ± 12, handgrip vs . cycle exercise, P = 0.0003). Remarkably, the isolated increase in afterload experienced by the myocardium during isometric handgrip exercise was more sensitive at unmasking sub‐clinical diastolic dysfunction in community dwelling individuals compared to cycle exercise (handgrip: n = 14 vs . n = 10; and cycle: n = 10 vs . n = 14, responders vs . non‐responders, respectively). Taken together, these data highlight the usefulness of isometric handgrip echocardiography at isolating myocardial diastolic relaxation abnormalities in community dwelling individuals, beyond that of dynamic cycle exercise. Future work should focus on confirming the sensitivity of this method in individuals at risk for or with diagnosed heart failure. Support or Funding Information AHA 16SDG27260115 and the Harry S. Moss Heart Trust. This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal .