Background: Cardiovascular magnetic resonance (CMR) imaging is considered the gold standard for the evaluation of ventricular morphology and function. We implemented wave intensity analysis and the reservoir-wave hypothesis for CMR to assess ventriculo-arterial coupling non-invasively. We present the feasibility of both methods.

Methods: Wave intensity analysis was performed on patients undergoing renal denervation (RDN, Symplicity Flex catheter) for treatment of hypertension (n=9 32–65 years 4 males office blood pressure (BP) 192/104 ±16/14 mmHg). Phase-contrast CMR flow data was acquired in the ascending aortic pre-RDN and at 6 months follow-up. Wave intensity was derived from the product of aortic blood flow velocity differentials and fractional changes of aortic area. The reservoir-hypothesis was implemented for CMR-derived velocity and area data in a Phyton script, using the Levenberg-Marquardt nonlinear fitting algorithm. Feasibility of extracting reservoir-wave parameters (i.e. diastolic time constant, arterial compliance, and asymptotic area value) was tested in an additional cohort of normotensive subjects (n=20 20–74 years 17 males).

Results: Wave intensity analysis was feasible in hypertensive patients, with an increase in peak forward compression wave post-RDN (7.9±3.8 pre-RDN vs. 9.8±2.5 post-RDN, p=0.046), suggesting improved ventricular contractility in response to altered downstream impedance. Systolic BP reduced (−21±26 mmHg, p=0.040) post-RDN, whilst ejection fraction and LV mass were unchanged. Reservoir wave parameters were physically realistic, with a reasonably tight distribution, the fitting algorithm converging robustly in 19/20 test cases.

Conclusion: Routine CMR data can provide valuable insight into ventriculo-arterial coupling and reservoir-wave parameters. Pilot data suggest that RDN improves left ventricular contractility.