Ten subjects with normal hemodynamics were studied during elective cardiac catheterization with right and left heart multisensor micromanometry to assess hemodynamic responses to the Mueller maneuver. Simultaneous right and left circulatory hemodynamics and left ventricular, pulmonary arterial, and aortic pressures were recorded, in addition to pulmonary arterial and aortic flow velocities. Steady-state cardiac outputs were determined by thermal dilution. Aortic systolic and mean pressures were not significantly changed during the Mueller maneuver, in contrast to a lower diastolic (p = .019) and higher pulse pressure (p = .016). Mean right atrial pressure (± SE) decreased from 7 1 to -17 + 4 mm Hg (p = .0002) and the right atrial "x" descent was markedly accentuated. Left ventricular end-diastolic pressure decreased from 12 + 4 to -3 ± 13 mm Hg (p = .0025). Systemic vascular resistance and left ventricular peak positive dP/dt were increased during the Mueller maneuver (p < .02), cardiac output and stroke volume were reduced (p < .05), and there was no significant change in heart rate. Right and left peak flow velocities showed a trend toward a bilateral decrease (right, p = .054; left, p > .1), and times to peak flow velocity were increased in the pulmonary artery (p = .007) and reduced in the aortic root (p = .03). Normal subjects were studied separately by pulsed Doppler echocardiography. During the sustained Mueller maneuver, the internal jugular and right ventricular dimensions decreased, and superior vena cava Doppler flow was reduced. These data demonstrate reduced flow through the right and left heart chambers during a sustained Mueller maneuver in humans, in contrast to prior theory and animal data suggesting that right heart flow is increased during sustained forced inspiratory effort.

The coexistence of different clinical syndromes due to atherosclerosis in different organs is not rare and emphasizes the diffuse nature of this vascular process. Although renovascular disease may cause hypertension and/or renal insufficiency, it may also occur in the absence of the usual clinical markers that suggest renovascular hypertension. We report a patient with stable coronary anatomy who presented with crescendo angina pectoris. Diagnosis of renovascular hypertension was made by screening renal angiography at the time of the cardiac catheterization. Renal artery stenting resulted in stabilization of the coronary syndrome and obviated the need for further coronary intervention. To our knowledge, this is the first case of renovascular hypertension precipitating an unstable coronary syndrome in a patient with documented stable coronary anatomy. Review of the literature supports that patients undergoing cardiac catheterization are a high risk population for renovascular disease, particularly in the presence of other predictive factors such as documented coronary artery disease, older age, female gender, congestive heart failure, peripheral vascular disease, renal insufficiency, and smoking. Firm recommendations for routine screening renal angiography in patients undergoing peripheral or coronary angiography will need further studies.

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