Predictors of Exercise Capacity in Dilated Cardiomyopathy with Focus on Pulmonary Venous Flow Recorded with Transesophageal Eco-Doppler

Figure 1. Measurement of the mitral flow velocity (top) and the pulmonary venous flow velocity (middle) with the left ventricular diastolic pressure curve (bottom). EKG = electrocardiogram; QRS = EKG waves related to ventricular depolarization; BFV = blood flow velocity; E = peak velocity of the early mitral flow; EDT = deceleration time of the early mitral flow; A = peak velocity of the late mitral flow; AD = duration of the late mitral flow; S = peak systolic velocity of the pulmonary venous flow; Svti = systolic velocity integral of the pulmonary venous flow; D = peak diastolic velocity of the pulmonary venous flow; Dvti = diastolic velocity integral of the pulmonary venous flow; PVa = peak velocity of the reverse flow at atrial contraction; PVa-d = duration of the reverse flow; LVa = increase in the ventricular pressure due to atrial systole; Pre-a = pressure before atrial contraction; EDP = left ventricular end-diastolic pressure. The vertical dashed lines indicate the simultaneous start of the antegrade flow through the mitral valve and the retrograde flow into the pulmonary vein at atrial contraction; the mitral waves (top) are negative since transmitral flow is away from the…

Figure 2. Flowchart explaining the enrolment criteria of our study group. DCM = dilated cardiomyopathy; pts = patients; NYHA = New York Heart Association functional classification; CPX = cardiopulmonary exercise testing.

Figure 3. TEE recording of the mitral and pulmonary venous flow velocity in a patient with DCM showing a fairly normal peak VO2 (21 mL/kg/min). On the left, mitral flow velocity is displayed (bottom), and at the top, there is a 2D image showing the location of the sample volume in the LV (at the mitral annulus); the E/A ratio of the mitral waves was 0.7. On the right, the pulmonary venous flow is shown (bottom), and at the top, there is a 2D image showing the sample volume location 1 cm beyond the orifice of the left upper pulmonary vein with the left atrium, as indicated by the arrow: the systolic fraction of the venous flow was normal (82%); Arv-A was also normal (−39 ms), indicating a delayed relaxation of the LV with no increase in the filling pressure. TEE = transesophageal Doppler echocardiography; FV = flow velocity; VFV = venous flow velocity.

Figure 4. TEE recording of the mitral and pulmonary venous flow velocity in a patient with DCM and a reduced peak VO2 (12 mL/kg/min). On the left, mitral flow velocity is displayed (in this case, mitral flow was attained with a transthoracic approach); the E/A ratio of the mitral waves was 0.7, the same E/A ratio as in the patient in Figure 3. On the right, pulmonary venous flow is shown: the systolic fraction of the venous flow, differently from the case illustrated in Figure 3, was reduced (<50%), indicating this time a restriction of LV filling that predicts an increase in the Pre-a filling pressure. Arv-A was not computed as it is difficult to pinpoint the beginning of the mitral A-wave (precociously fused with the E-wave). There was a broadening of the pulmonary Doppler signal, so modal velocity was traced. TEE = transesophageal Doppler echocardiography; FV = flow velocity; VFV = venous flow velocity.

Figure 5. Dot histogram and ROC curve of S Fract in predicting the peak VO2 > and ≤14 mL/kg/min. The best S Fract cutoff was found at 59%, with an area under the curve of 68%, p < 0.001. Sens = sensitivity; Spec = specificity; S Fract = systolic fraction; PVF = pulmonary venous flow.

Figure 6. Means plot to compare the peak VO2 in three different categories of progressively increased LV filling pressure by TEE. Only the third group (pre-A increase in pressure) is significantly different from the first (no increase in LV filling pressure) and the second (isolated LV telediastolic restriction). For each group, the individual peak VO2 values with the mean and the standard error of the mean are reported. LV = left ventricle; telediast restr = telediastolic restriction (isolated increased telediastolic filling pressure); pre-a restr = increased pre-a pressure; ns = not significant.