Page 19 - CBAC Newsletter 2015

The Kovács ‘lab’ consists of only one small room with about four or five computers and multiple white boards on the
opposite wall. The walkway is narrow enough that one can just swing around in a swivel chair to get to the opposite
side but yet in this space, there is a lot going on. It is here that Dr. Sándor Kovács and members of his research
group employ multidisciplinary methods of engineering, physics, physiology, clinical cardiology, and the biomedical
sciences to do their work.

Motivation for Research

We are unusual in the sense that we are not really a ‘Lab’ at all, we are a theory group and solve human
cardiovascular physiology problems encountered in the practice of cardiology using theoretical insights, modeling etc
and validate those insights/model-based predictions using (primarily) human physiologic data obtained via cardiac
catheterization, echocardiography or cardiac MRI (at CORTEX)

I encounter practical, unsolved physiology problems frequently during discussions with colleagues and as part of
heart function assessment in the cath lab, echo lab and MRI lab. I am passionate about a causality based, rather
than correlation based characterization of heart function, through which more accurate and specific diagnoses can
be made. A causality based approach of diastolic function quantitation also provides an objective method for
assessing the impact of alternative therapies.

What are your future goals or what do you expect to accomplish in the next few years?

Continued investigation of cardiovascular physiology using causality based modeling, amenable to verification using
human, in-vivo data, and translation of novel methodology for noninvasive imaging.

Proudest Achievements

I am proudest of the dozens of doctoral students I have mentored– in physics, BME and MSTPs and capable
cardiology fellows I have had the good fortune to train and learn from over the years. We were able to clarify the rule
(a differential equation) that all hearts obey when they fill (all hearts are suction-pumps), thereby advancing the
method of echocardiography based diastolic function analysis from a descriptive method to a causality based
method by solving ‘the inverse problem of diastole’. This insight has led to major new physiologic understanding in
terms of the ‘constant-volume pump’ attribute of the 4-chambered heart; causality based definition of the reservoir,
conduit and booster pump function of the atrium; establishing that the volume of the LV at diastasis is the in-vivo
‘equilibrium volume’; accurate prediction of the duration of the systolic and diastolic phases of the cardiac cycle as a
function of heart rate; finding the long sought for solution to the ‘load independent index of diastolic function
problem’; fractionation of transmitral flow deceleration time into its chamber stiffness and chamber relaxation
components; and proof that the LV ejection fraction, usually considered an index of contractility or systolic function,
is in fact, an informative index of diastolic function! These achievements were facilitated by support of the Cardiac
MR Lab, directed by Sam Wickline, MD and the staff of the Cardiac Cath Lab at Jewish hospital and BJH.

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