The exercise-induced changes in left ventricular filling in patients with coronary artery disease are poorly understood. Therefore these changes were studied in relation to a noninvasive indicator of ...exercise pulmonary venous congestion, the lung-to-heart (L:H) ratio on symptom-limited thallium stress testing. Fifty-six patients undergoing diagnostic treadmill testing were studied; 50 of them had technically adequate Doppler recordings and became the subjects of this study. Doppler left ventricular filling was assessed with patients in the supine position both before and after exercise. Measurements included early (E) and late (A) filling velocities, their ratio, the diastolic time-velocity integral, and the diastolic filling time. The L:H ratio was considered abnormal if it was greater than the upper 95% confidence limit for a separate group of normal subjects. Twelve subjects had a documented prior myocardial infarction, 16 had stress-induced ischemia, and 20 had abnormal L:H ratios. A greater E and a longer diastolic filling time in the group with an abnormal L:H ratio were the only postexercise measurements that differed; however, E was the only filling parameter that both differed between groups after exercise (abnormal L:H group 87 +/- 25 cm/sec; normal 68 +/- 20 cm/sec; p < 0.01) and whose change from rest to after exercise was significantly different (p < 0.05). Since Doppler velocities are directly related to instantaneous gradients, the higher E in patients with evidence of exercise pulmonary congestion suggests a higher exercise early diastolic left atrial pressure.
Lipomatous hypertrophy of the interatrial septum consists of the abnormal accumulation of fatty tissue. We report a patient with unsuspected massive lipomatous hypertrophy of the interatrial septum ...scheduled to undergo coronary artery surgery. This patient had experienced atrial arrhythmias and obstructive symptoms preoperatively that were ascribed to her coronary artery disease (CAD). The perioperative anesthetic and surgical management of patients with lipomatous hypertrophy of the interatrial septum and CAD is discussed.
Previous reports have suggested that atrioventricular (AV) flow disturbances accompanying atrial myxomas mimic mitral stenosis. Two patients complaining of orthostatic syncope and positional ...intolerance had a large right and left atrial myxoma, respectively. Doppler flow records showed abrupt early diastolic flow cessation and normal velocity half-times, unlike AV valve stenosis. Large, obstructing atrial myxomas may behave as ball valves.
A method is described for noninvasive cardiovascular evaluation of vasovagal syncope. Continuous electrocardiogram, impedance cardiogram, and finger-cuff blood pressure recordings are acquired and ...analyzed on a beat-by-beat basis for calculation of heart rate, cardiac contractility, cardiac output, mean arterial pressure, and systemic vascular resistance. In a patient with near-syncopal head-upright tilt response, a 200% increase in cardiac contractility 20% decrease in mean arterial pressure, and 66% reduction in systemic vascular resistance was demonstrated. Comprehensive cardiovascular assessment of orthostatic stress response may improve diagnosis and understanding of vasovagal syncope.< >
To test the hypothesis that pulsed Doppler ultrasound spectral properties of bounded fluid jets related to orifice size, in vitro examinations were performed using a hydraulic simulator (standpipe, ...compliant receiving chamber, and variable round orifice). Orifices of 17.3, 7.9, 4.5 and 2.0 mm2 area resulted in flows of 4.0, 1.7, 1.1 and 0.3 L/min respectively. We interrogated the fluid jet at midchamber (MC) and at the chamber will impact site (IS), and the resulting Doppler shifts were displayed on a spectrum analyzer. For each orifice size, 36 independent observations were made at each interrogation site. At site MC, a characteristic low break frequency (K) was observed in an otherwise flat spectrum. The spectrum from site IS were peaked, with the peak described by center frequency (P), peak amplitude (A), and frequency at which the peak merged with the background (X). As orifice size increased from smallest to largest, monotonic changes in K (1020-440 Hz), P(330-750 Hz), A (8-28 db), and X (840-2660 Hz) were observed. Standard deviation about each mean ranged from 9 to 28%. Orifice shape, receiving chamber viscosity, and standpipe pressure significantly influenced the spectra. These data suggest that quantification of jet flow is possible in vitro using spectral analysis and pulsed Doppler ultrasound.
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