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In aortic stenosis (AS), postextrasystolic potentiation (PESP), a measure of contractile reserve, has been demonstrated by an increased aortic valve gradient (AVG) after a ventricular extrasystole (VE). We studied age-related changes in PESP in 20 consecutive patients (age, 65-89 years) with significant AS (aortic area <or= 1.0 cm(2)) on cardiac catheterization with VE on AVG pressure recording. Hemodynamics and LV systolic time intervals were averaged from three consecutive beats and from the post-VE beat. Changes (Delta) in AVG, pre-ejection period/LV ejection time ratio (PEP/LVET), aortic diastolic pressures (AoDP), and LV end-diastolic pressures (LVEDP) were calculated. Age was inversely correlated with DeltaAVG (r = -0.84, P = 0.0001), with DeltaPEP/LVET (r = -0.87, P = 0.0001), and with DeltaAoDP (r = -0.89, P = 0.0001), but not with DeltaLVEDP (r = 0.23, P = 0.31). On multivariate analysis, only age was associated with DeltaAVG (r(2) = 0.72, P = 0.0001). There was an age-related decline in PESP in patients with AS, which was accompanied by changes in contractile reserve and afterload reduction, but independent of preload reserve.

Bacteremia after diagnostic cardiac catheterization is uncommon, but bacteremia after percutaneous transluminal coronary angioplasty (PTCA) has not been studied prospectively. Unlike diagnostic cardiac catheterization, PTCA involves the use of an indwelling arterial sheath after completion of the procedure, which is connected to a pressurized heparin solution, both of which increase the risk of local infection and/or bacteremia. During a 16-week period, we prospectively evaluated patients undergoing 164 PTCA procedures in order to determine the frequency of bacteremia and the significance of fever in this patient population. Blood cultures were obtained from the femoral catheter at the conclusion of the procedure and again 30 min later from the indwelling arterial sheath. Temperature was recorded every 30 min for 2 h following PTCA, then every 4 h over the subsequent 36-hr period. Bacterial isolates were recovered from 23/286 blood cultures (8.0%), with Staphylococcus epidermidis the most common organism present (74%). Only one isolate of Staphylococcus aureus was considered to represent true bacteremia and corresponded with the only documented infectious complication. Fever, defined as > or = 101 degrees F developed in four (2.4%) patients but was procedure related in only one case. The use of the ipsilateral femoral artery for repeat procedures was not associated with either positive blood cultures or difference in maximum temperature elevation. We conclude the overall risk of bacteremia after PTCA is low; therefore, antimicrobial prophylaxis is not warranted.