Exercise Stress Echocardiography in the Diagnostic Evaluation of Heart Failure with Preserved Ejection Fraction

Figures

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  Figure 1. Changes in the transmitral inflow profile at rest and throughout exercise in a patient with heart failure and preserved ejection fraction. During peak exercise (80 watts), the transmitral E and A waves were indistinguishable owing to fusion. Continuous image acquisition allowed for the identification of an E wave of 100 cm/s at 60–watt exercise, and the E/e′ ratio at this stage was elevated (E/e′ ratio, 15.5). Invasive exercise right heart catheterization revealed that the pulmonary capillary wedge pressure (PCWP) was normal at rest (9 mmHg); however, it increased to 26 mmHg during peak exercise (80 watts). Although the E and A waves were no longer fused in the early recovery phase, the E/e′ ratio was 12.9. The invasively measured PCWP decreased to 19 mmHg (<25 mmHg) at 1 min post–exercise. HR, heart rate.

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  Figure 2. Exercise-induced ultrasound B-lines with simultaneously measured pulmonary capillary wedge pressure (PCWP) in a patient with heart failure and preserved ejection fraction. The patient demonstrated mildly elevated PCWP (19 mmHg, red line) without ultrasound B-lines at rest. During peak exercise (40 watts), the PCWP increased to 33 mmHg with marked V waves (71 mmHg), and multiple B-lines developed (yellow arrowheads).

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  Figure 3. Heightened ventricular interdependence due to worsening tricuspid regurgitation (TR) during exercise in a patient with heart failure and preserved ejection fraction. The patient had persistent atrial fibrillation and moderate-to-severe TR at rest. The TR velocity was 2.5 m/s, and the estimated right atrial pressure based on inferior vena cava measurements was 15 mmHg. During peak exercise (20 watts), the TR dramatically worsened with incomplete coaptation of the tricuspid valves, resulting in paradoxical reduction in TR velocity (1.9 m/s). A significant increase in TR during exercise caused greater ventricular interdependence, contributing to reduced exercise capacity (peak oxygen consumption [VO2], 7.1 mL/min/kg).

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  Figure 4. Key parameters in diastolic stress echocardiography. A 72-year-old woman who presented with exertional dyspnea was referred for diastolic stress echocardiography. She had a normal ejection fraction (61%), slightly elevated B-type natriuretic peptide (NP) levels (48.2 pg/mL), borderline E/e′ ratio (10.9), and a normal tricuspid regurgitation (TR) velocity (2.4 m/s). During peak exercise, the E wave and E/e′ ratio increased (16.9), with a concomitant elevation in TR velocity (3.8 m/s). LV, left ventricular.

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  Figure 5. EACVI/ASE recommendations and HFA-PEFF algorithm for the diagnosis of HFpEF using exercise stress echocardiography. (A) In the EACVI/ASE recommendations, the test is considered abnormal (i.e., HFpEF) when all three criteria are met. (B) In the HFA-PEFF algorithm, the E/e′ ratio and TR velocity during exercise are used to add points to the resting HFA-PEFF score calculated in step 2. If the total score is ≥5 points, the diagnosis of HFpEF is confirmed. ASE, American Society of Echocardiography; EACVI, European Association of Cardiovascular Imaging; HFA-PEFF algorithm, a consensus-based algorithm proposed by the Heart Failure Association of the European Society of Cardiology; HFpEF, heart failure with preserved ejection fraction; TR, tricuspid regurgitation; NP, natriuretic peptide.

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  Figure 6. A case of cardiac output (CO) reserve limitation during exercise. A 79-year-old woman with obesity (body mass index, 30 kg/m2) was referred to our echocardiographic laboratory for the evaluation of unexplained dyspnea on exertion. Her NP levels were within the normal range (N-terminal pro-brain NP, 65 pg/mL). The results of resting echocardiography were also normal; however, cardiac magnetic resonance imaging showed remarkable epicardial fat tissue (yellow arrowhead). Diastolic stress echocardiography combined with expired gas analysis showed CO reserve limitation during exercise relative to increases in VO2 (CO, 2.9 to 3.9 L/min; VO2, 189 to 549 mL/min; CO reserve, 48%). The septum became flattened in the parasternal short-axis view during peak ergometry exercise (yellow arrowhead), suggesting that enhanced ventricular interdependence might have contributed to the CO reserve limitation due to reduction in LV preload in addition to chronotropic incompetence. LVOT, left ventricular outflow tract.