Response to Letter Regarding Article, “Restrictive Left Ventricular Filling Pattern Does Not Result From Increased Left Atrial Pressure Alone”
We are grateful for the interest in our article1 expressed by Razzolini and Tarantini. They agree that we have demonstrated that the restrictive filling is not due to an overfilled ventricle. However, they are concerned that this pattern is not due to diastolic dysfunction but instead results from systolic dysfunction. Although restrictive filling is most common in patients with heart failure associated with a reduced ejection fraction, it also occurs in patients with severe heart failure and a normal ejection fraction.2
The animal model of restrictive filling we used has both systolic and diastolic dysfunction. We have previously demonstrated that key components of restrictive filling are related to the diastolic dysfunction. During the progressive development of heart failure in this model, the reduced and delayed mitral annular velocity correlates closely with the degree of slowing of left ventricular relaxation, and the shortened E-wave deceleration time is due to increased effective diastolic chamber stiffness.3,4 The relations of these parameters to relaxation and to chamber stiffness are further supported by theoretical analysis of the physical basis of filling.2,5 These analyses indicate that the filling dynamics will be determined by relaxation and operating chamber stiffness, regardless of the size of the left ventricle or ejection fraction. It must be recognized that in many but not all situations, slowed relaxation is associated with systolic dysfunction. The effective operating chamber stiffness, not the overall end-diastolic pressure-volume relation, determines the E-wave deceleration time. An increased chamber stiffness may be due to an upward and leftward shift of the end-diastolic pressure-volume relation or to rightward displacement onto a stiffer portion of the curvilinear end-diastolic pressure-volume relation.
Thus, our study1 shows that the restrictive filling pattern characterized by a short E-wave deceleration time and a reduced and delayed mitral annular velocity does not result from an elevated left atrial pressure alone, but is rather a consequence of slowed left ventricular relaxation and increased effective diastolic chamber stiffness.
Masutani S, Little WC, Hasegawa H, Cheng H-J, Cheng C-P. Restrictive left ventricular filling pattern does not result from increased left atrial pressure alone. Circulation. 2008; 117: 1550–1554.
Little WC. Diastolic dysfunction beyond distensibility: adverse effects of ventricular dilatation. Circulation. 2005; 112: 2888–2890.
Ohno M, Cheng CP, Little WC. Mechanism of altered patterns of left ventricular filling during the development of congestive heart failure. Circulation. 1994; 89: 2241–2250.
Little WC, Ohno M, Kitzman DW, Thomas JD, Cheng CP. Determination of left ventricular chamber stiffness from the time for deceleration of early left ventricular filling. Circulation. 1995; 92: 1933–1939.