Four year follow up of aortic valve replacement for isolated aortic stenosis: a link between reduction in pressure overload, regression of left ventricular hypertrophy, and diastolic function.

OBJECTIVE: To evaluate changes in left ventricular function and the impact of ventricular hypertrophy and pressure gradient early and late after aortic valve replacement in patients with isolated aortic stenosis. DESIGN: 41 patients with isolated aortic stenosis and normal systolic function underwent cross sectional and Doppler echocardiography two months before and two weeks and four years after aortic valve replacement. RESULTS: Early after the operation, left ventricular mass index (mean (SD)) decreased from 187 (44) g/m(2) to 179 (46) g/m(2), because of a reduction in end diastolic diameter (p < 0.05). Aortic pressure gradients were reduced, as expected. Isovolumic relaxation time was reduced from 93 (20) ms to 78 (12) ms, and deceleration time from 241 (102) ms to 205 (77) ms (p < 0.05). At four years, left ventricular mass index was further reduced to 135 (30) g/m(2) (p < 0.01) as a result of wall thickness reduction in the interventricular septum (from 14 (1.6) mm to 12 (1.4) mm, p < 0.01) and the posterior wall (from 14 (1.6) mm to 12 (1.3) mm, p < 0.01). Diastolic function, expressed by a reduction in isovolumic relaxation time from 93 (20) ms to 81 (15) ms (p < 0.01) and deceleration time from 241 (102) ms to 226 (96) ms (p < 0.05), remained improved. Prolonged isovolumic relaxation time was associated with significant septal and posterior wall hypertrophy (wall thickness > 13 mm) (p < 0.05), whereas prolonged deceleration time was related to high residual gradient (peak gradient > 30 mm Hg ) (p < 0.01). CONCLUSIONS: Left ventricular diastolic function improves early after surgery for aortic stenosis in parallel with the reduction in the aortic gradient. However, prolongation of Doppler indices of myocardial relaxation and ventricular filling is observed in patients with significant left ventricular hypertrophy and a residual pressure gradient early after surgery. At four years postoperatively, diastolic function remains improved.

Routine arterial oxygen saturation monitoring is not necessary during transesophageal echocardiography.

BACKGROUND: Transesophageal echocardiography (TEE) is now an established adjunct to routine echocardiography, its diagnostic impact making it an invaluable first-line diagnostic procedure in many cardiac conditions. However, there is no unanimity in the way the transesophageal procedure is carried out, especially with regard to the need for antibiotic prophylaxis, sedation, and the monitoring of oxygen saturation. HYPOTHESIS: This study was prospectively undertaken (1) to determine the presence and magnitude of oxygen desaturation and (2) the changes in heart rate and blood pressure following sedation for routine TEE in an unselected and consecutive group of patients to identify those at high risk. METHODS: Arterial oxygen saturation, heart rate, and systolic, diastolic, and mean blood pressure were monitored in 106 consecutive patients undergoing routine transesophageal echocardiography. Ninety-four (89%) patients received intravenous sedation with midazolam. RESULTS: Three min after midazolam administration there was a drop in oxygen saturation from 97 +/- 2.5 to 95 +/- 2.9 (p < 0.001), in systolic blood pressure from 139 +/- 19.5 to 124.8 +/- 22.2 mmHg (p < 0.001), in diastolic blood pressure from 86.6 +/- 19.9 to 77.5 +/- 17.7 mmHg (p < 0.001), and in mean blood pressure from 108.3 +/- 18 to 95.6 +/- 28.8 mmHg (p < 0.001). After introduction of the transesophageal probe and during the examination, there was a further drop in oxygen saturation with a maximum drop at the 15th min of the examination (93.7 +/- 3.7 vs. 97 +/- 2.5, p < 0.001). The maximum blood pressure drop occurred at the 12th min into recovery: systolic blood pressure dropped from 139 +/- 19.5 to 118 +/- 20.8 mmHg (p < 0.001), diastolic blood pressure from 86.6 +/- 16.9 to 75.8 +/- 17.9 mmHg (p < 0.005), and mean blood pressure from 108.3 +/- 18 to 92.5 +/- 19.4 mmHg (p < 0.01). Patients with congestive heart failure had a greater drop in oxygen saturation compared with patients who were not in heart failure (p < 0.01). Twelve patients did not receive any sedation; however, they all showed a drop in oxygen saturation from 97.8 +/- 2.3 to 94.6 +/- 3.4 (p < 0.001), with a maximum drop at the 15th min during the transesophageal examination. CONCLUSION: In patients with no chronic obstructive airway disease who are not in congestive heart failure, routine oxygen saturation monitoring is not deemed necessary during transesophageal examination. The cause of hypoxemia during the procedure is not only related to sedation but also to esophageal intubation.

Diastolic aortic pressure rise during percutaneous transluminal coronary angioplasty: an index of left ventricular systolic dysfunction.

OBJECTIVES: To investigate the relation between diastolic aortic pressure response and left ventricular systolic dysfunction during percutaneous transluminal coronary angioplasty. BACKGROUND: The abnormal diastolic blood pressure rise during exercise in patients with coronary artery disease probably reflects left ventricular systolic dysfunction rather than the number of stenosed coronary arteries. METHODS: Aortic blood pressures and left ventricular systolic function indices were estimated in 26 patients with single proximal stenosis of the left anterior descending coronary artery both before and during angioplasty. RESULTS: During coronary angioplasty all patients presented an increase in diastolic aortic pressure (P << 0.001), 8-12s before intracoronary electrocardiographic changes. During acute ischaemia there was a decrease in left ventricular ejection fraction (P << 0.001) and stroke volume (P << 0.001) and an increase in end systolic volume (P << 0.001) and left ventricular end diastolic pressure (P << 0.001). No statistically significant changes were observed in systolic blood pressure or heart rate. The aortic diastolic pressure increase was correlated with the decrease in ejection fraction (r = -0.95, P << 0.001) and with the increases in end systolic volume (r = 0.86, P << 0.001) and left ventricular end diastolic pressure (r = 0.85, P << 0.001). CONCLUSIONS: The rise in diastolic aortic pressure during percutaneous transluminal coronary angioplasty occurs earlier than intracoronary electrocardiographic changes and is related to ischaemic left ventricular systolic dysfunction.

Increased response of diastolic blood pressure to exercise in patients with coronary artery disease: an index of latent ventricular dysfunction?

OBJECTIVE: To determine whether an abnormal response of diastolic blood pressure during treadmill exercise stress testing correlated with the number of obstructed vessels and with left ventricular systolic function in patients with coronary artery disease. DESIGN: Diastolic blood pressure was measured invasively during exercise stress testing and coronary angiograms and left ventriculograms were obtained at rest in patients with coronary artery disease. The abnormal (> or = 15 mm Hg) diastolic blood pressure response was compared with the number of obstructed coronary arteries and with left ventricular systolic function. SETTING: Two tertiary referral centres. PATIENTS: 50 consecutive patients (mean age 57 years) with coronary artery disease. MAIN OUTCOME MEASURES: The increase in diastolic blood pressure during exercise and its correlation with the appearance and disappearance of ST segment deviation, resting left ventricular systolic function, and the number of obstructed coronary arteries. RESULTS: Group 1: 10 (20%) patients (three with one, four with two, and three with three vessel coronary artery disease) (mean (SD) age 54.7 (12) years) had an abnormal diastolic blood pressure response that appeared 1.2 (0.3) min before ST segment deviation and became normal 0.9 (0.3) min after the ST segment returned to normal. Group 2: 40 (80%) patients (12 with one, 16 with two, and 12 with three vessel coronary arteries disease) (aged 56.8 (8.2) years) had a normal diastolic blood pressure response to stress testing. The ejection fraction (46.3 (5)%) and cardiac index (2.6 (0.1) 1/min/m2) in group 1 were less than in group 2 (61.6 (4.2)% and 3.8 (0.3) 1/min/m2 respectively, p < or = 0.001). The end systolic volume was greater in group 1 than in group 2: 38.7 (0.7 ml/m2 v 28.2 (2.1) ml/m2, p < or = 0.001. CONCLUSION: In patients with coronary artery disease an abnormal increase in diastolic blood pressure during exercise stress testing correlated well with left ventricular systolic function at rest but not with the number of obstructed coronary arteries. The abnormal response of diastolic blood pressure probably reflects deterioration of myocardial function.