Feeding Induces Left Atrial Compression and Impedes Cardiac Filling in Patients With Large Hiatal Hernia.

BACKGROUND: Patients with large hiatal hernias (HH) frequently experience postprandial dyspnea. The aim of this study was to evaluate whether feeding induced cardiac compression in these patients using echocardiography. METHODS: Transthoracic echocardiography was performed during fasting and 30 min after feeding (300 g rice pudding) in patients with HHs (n = 32; mean age, 72 ± 9 years). A subset of patients (n = 15; mean age, 76 ± 6 years) were evaluated postoperatively. RESULTS: Preoperatively, feeding decreased left atrial (LA) volumes (maximal 27.4 ± 11.3 vs 19.2 ± 9.7 mL/m2, P < .001; minimal 13.1 ± 7.0 vs 6.9 ± 5.1 mL/m2, P < .001), and increased LA inflow velocities (systolic wave 0.62 ± 0.14 vs 0.77 ± 0.17 m/sec, P < .01; diastolic wave 0.46 ± 0.13 vs 0.59 ± 0.13 m/sec, P < .01), mitral inflow velocities (E wave 0.79 ± 0.17 vs 0.94 ± 0.19 m/sec, P < .01; A wave 0.93 ± 0.20 vs 1.05 ± 0.22 m/sec, P < .01), and E/E' ratio (12.1 ± 2.7 vs 13.7 ± 3.9, P < .01). Cardiac output (6.3 ± 1.6 vs 7.24 ± 2.0 L, P < .01) increased postprandially by marked heart rate augmentation (68.8 ± 7.0 vs 84.2 ± 8.4 beats/min, P < .01), with modest stroke volume increase (88.5 ± 16.7 vs 94.3 ± 19.5 mL, P = .03). After HH surgery, feeding did not change LA volumes (maximal 52.9 ± 13.6 vs 53.4 ± 12.5 mL, P = .89; minimal 28.6 ± 12.2 vs 27.4 ± 8.7 mL, P = .59) or E/E' ratio (10.9 ± 2.1 vs 11.3 ± 2.3) and induced more modest alterations in LA inflow (systolic wave 0.58 ± 0.17 vs 0.68 ± 0.16 m/sec, P = .01; diastolic wave 0.41 ± 0.12 vs 0.47 ± 0.13 m/sec, P = .01) and mitral inflow (E wave 0.69 ± 0.15 vs 0.80 ± 0.13 m/sec, P < .01; A wave 0.92 ± 0.13 vs 1.01 ± 0.18 m/sec, P = .02). Postoperatively, feeding increased cardiac output by substantial stroke volume augmentation (81.9 ± 16.5 vs 90.8 ± 16.0 mL, P = .01), with only modest increase in heart rate (69.8 ± 9.1 vs 75.9 ± 10.5 beats/min, P < .01). CONCLUSIONS: Feeding produces marked LA compression in patients with HHs, inducing compensatory exaggerated responses in cardiac inflow and hemodynamic status. These compensatory mechanisms improve postoperatively following resolution of LA compression, likely explaining the debility noted preoperatively.

A novel parasternal transthoracic echocardiographic window for detecting coronary ostial dilation after modified Bentall surgery.

BACKGROUND: During the modified Bentall surgery (aortic root replacement), a cuff of native aorta is implanted, together with the coronary ostium, into the aortic graft. Multi-detector computed tomography (MDCT) imaging can accurately assess the coronary ostial anastomosis site post-surgery. In this study, we assessed the feasibility of imaging the coronary ostial anastomosis site using transthoracic echocardiography (TTE). METHODS: Patients (n = 14, mean age 65 ± 12 years, 79% males) with previous Bentall surgery underwent TTE study, with MDCT (64-slice) as the reference standard. TTE used conventional and novel acoustic windows to interrogate the coronary ostia. RESULTS: All coronary ostia (n = 28) were well-visualized with MDCT. The optimum TTE acoustic window for visualizing the coronary ostia was a superiorly positioned parasternal short-axis view with the probe tilted towards the left shoulder, medially angulated for the right coronary artery ostia (RCAos) and laterally angulated for the left main coronary artery (LMAos). In this off-axis position, 10 (71%) LMAos and 13 (93%) RCAos could be visualized. In the conventional parasternal views, only 5 (36%) RCAos and no LMAos could be visualized. TTE underestimated the diameter of the LMAos (10.0 ± 2.4 mm TTE vs. 13.4 ± 2.7 mm MDCT, p = 0.007), but was similar to MDCT for the RCAos (9.8 ± 3.1 mm TTE vs. 11.1 ± 3.2 mm MDCT, p = 0.10). CONCLUSIONS: We report a novel TTE acoustic window to image the coronary ostia of post-Bentall surgery patients. Although TTE underestimates the left coronary ostium size, recognition of the ostial dilation with TTE appears feasible in most patients. Those that cannot be imaged will require alternative imaging modality such as MDCT.