Mark E. Leithe

Relationship between central hemodynamics and regional blood flow in normal subjects and in patients with congestive heart failure.

Central and regional (hepatic, renal, and limb) hemodynamic data are presented for a normal population (n = 16) and for a group of patients with congestive heart failure (n = 64). The patient population represented a wide spectrum of severity of congestive heart failure. Various relationships between central and regional hemodynamics were analyzed. The results indicate that in congestive heart failure blood flow to hepatic, renal, and limb regions is significantly decreased, and that this decrease is proportional and linearly related to the reduction in cardiac output. The vascular resistances of these regions correlated directly with systemic vascular resistance. Changes in renal vascular resistance and renal blood flow became attenuated as the severity of the heart failure advanced from moderate to severe and at higher levels of systemic vascular resistance. There was little to no correlation between systemic blood pressure and liver, kidney, and limb blood flow for the range of systemic pressures studied.

Ergonovine maleate testing during cardiac catheterization: a 10-year perspective in 3,447 patients without significant coronary artery disease or Prinzmetal's variant angina.

The utility of ergonovine testing for coronary artery spasm was assessed in 3,447 patients with angiographically insignificant (less than 50% diameter stenosis) or no coronary artery disease. No patients clinically had Prinzmetals variant angina. Overall, 4% had a positive ergonovine test result, defined by spasm causing greater than or equal to 75% focal stenosis. Complications related to ergonovine use occurred in 11 patients (0.03%). In a training sample of 1,136 patients (studied between 1980 and 1984), two independent predictors of spasm were found by using multivariate analysis: the amount of visible coronary artery disease on the coronary angiogram (p less than 0.0001) and a smoking history (p = 0.001). A model to predict spasm based on these variables was validated in a test group of 2,311 patients who received ergonovine from 1985 to 1989. This model allowed the identification of a subset of 400 patients in the validation sample who had a 10% positive test rate compared with a 2% positive test rate in the remaining patients. These results should permit clinicians who use provocative testing in the catheterization laboratory to reserve testing for the subset of this group of patients most likely to have abnormal findings.

Clonidine in congestive heart failure: A vasodilator with negative inotropic effects

Fourteen patients with moderately severe congestive heart failure (CHF) were given clonidine orally (0.2 and 0.4 mg doses) to determine the hemodynamic effects of a typical centrally acting vasodilator. The 0.2 mg dose significantly reduced mean systemic (15%) and mean pulmonary artery (20%) pressure; the corresponding reductions in vascular resistance were not as great because of a diminished cardiac output. Pulmonary capillary wedge pressure decreased significantly (27%). Heart rate decreased 11% and stroke volume remained unchanged. At a higher dose (0.4 mg), clonidine augmented these reductions but increased stroke volume modestly (15%). Isovolumic developed pressure/duration of isovolumic contraction and the duration of the preejection period were used as indexes of inotropy. After both doses, isovolumic developed pressure/duration of isovolumic contraction decreased dramatically (greater than or equal to 33%) and the preejection period increased substantially (greater than or equal to 18%) (both p less than 0.05). Compared with currently employed vasodilating agents, the centrally acting agent clonidine appears unique in that the drug-induced systemic and pulmonary arterial vasodilation are not accompanied by a commensurate improvement in ventricular systolic function. This lack of improvement appears to be a result of negative inotropic effects.

Balloon angioplasty of coarctation of the aorta evaluated with intravascular ultrasound imaging

Intravascular ultrasound images were employed to evaluate aortic coarctation before and after balloon angioplasty. Measurements obtained with use of an ultrasound imaging catheter correlated well with measurements made with digital aortography, both in the area of coarctation and in areas proximal and distal to it. The intravascular ultrasound images dramatically revealed dissection of the aortic wall and an intimal flap that was not appreciated on cineaortography or digital subtraction angiography. Intravascular ultrasound imaging may yield important morphologic information unavailable by other imaging techniques. Such information may allow more precise definition of the results of intravascular procedures and improve understanding of lesion characteristics predictive of a successful outcome.

Failure of balloon aortic valvuloplasty to result in sustained clinical improvement in patients with depressed left ventricular function

Although balloon aortic valvuloplasty usually results in acute hemodynamic improvement, recurrent symptoms often occur within several months. The current study was designed to determine whether clinical characteristics, including invasive hemodynamic parameters of left ventricular (LV) performance, are predictive of short-term patient outcome. Eighty-one consecutive patients were prospectively enrolled in the study protocol. High-fidelity dual sensor micromanometer catheters, digital ventriculography and aortography and Fick cardiac output were measured before and immediately after balloon aortic valvuloplasty. Stroke work was defined from pressure-volume loops. The acute hemodynamic results obtained in patients with overall improved symptoms were compared to those with recurrent symptoms at 3 months. Fifty-three patients (65%) were improved at 3-month evaluation (group 1), whereas 28 patients (35%) had either returned to symptoms at baseline (17), had undergone aortic valve replacement (3) or had cardiac death (8). Compared to patients with improved symptoms, patients with recurrent symptoms demonstrated a lower cardiac output, higher LV end-systolic volume, decreased LV ejection fraction, diminished LV stroke work and decreased LV peak positive dP/dt. The final aortic valve area and change in aortic valve area did not predict which patients would develop recurrent symptoms. Stepwise logistic regression revealed that LV ejection fraction was the only independent predictor of overall status at 3 months (p = 0.002). Eighty-four percent of patients with an ejection fraction greater than 45% were improved. In the group with an ejection fraction greater than 45%, less than half of the patients demonstrated improved symptoms at short-term followup. Parameters of LV performance can accurately predict short-term patient outcome after balloon aortic valvuloplasty.

The effect of age on central and regional hemodynamics

16 normal subjects, ranging in age from 24 to 79 years, underwent simultaneous central and regional (renal, hepatic and limb) hemodynamic measurements; the purpose of this investigation was to determine the relationship between these measurements and age. Cardiac index was inversely related to age, with a correlation coefficient of -0.53 (p less than 0.05). Renal blood flow correlated inversely with age at an r value of -0.52 (p less than 0.05). Although the correlation coefficients did not achieve statistical significance, several trends were noted with increasing age: systemic vascular resistance, renal, hepatic and limb vascular resistances, and mean systemic blood pressure increase and hepatic and limb flows decrease. In normal human subjects, certain central and regional hemodynamic parameters change with age; these changes may ultimately influence function and perhaps, drug disposition (liver and kidney) as well.

Intracardiac Echinococcal Cyst Causing Biventricular Cavity Obliteration

A 47-year-old male presented to the emergency room after an episode of exertional syncope. He denied palpitations, incontinence, dyspnea, or any prior syncope. An ECG and serum cardiac enzymes were normal. A computed tomographic angiogram performed to rule out pulmonary embolism revealed an intracardiac mass in the ventricular septum, measuring 5.0×5.0×4.7 cm (Figure [A]). Subsequent transthoracic echocardiography demonstrated cavity obliteration of the right ventricle from the mass. Figure. Intracardiac echinococcal cyst. A , Computed tomographic angiogram shows an intracardiac mass within the interventricular septum between the right …

Left ventricular performance and clinical outcome after repeat balloon aortic valvuloplasty

Excerpt The detailed baseline and acute changes in left ventricular performance characteristics during repeat balloon aortic valvuloplasty have not been evaluated relative to the initial procedure....