PubMed Health⌕ Search

Biomedical subjects

J B Hermiller

Publications and source records attributed to J B Hermiller.

At least 37 records · Page 2Linked to original sources
PubMed1995

Balloon aortic valvuloplasty in adults: failure of procedure to improve long-term survival.

OBJECTIVES: This study sought to determine the long-term outcome of adult patients undergoing percutaneous balloon aortic valvuloplasty. BACKGROUND: Percutaneous balloon aortic valvuloplasty has been offered as an alternative to aortic valve replacement for selected patients with valvular aortic stenosis. Although balloon aortic valvuloplasty produces an immediate reduction in the transvalvular aortic gradient, a high incidence of restenosis frequently leads to recurrent symptoms. Therefore, it is unclear whether balloon aortic valvuloplasty impacts on the long-term outcome of these patients. METHODS: Clinical, hemodynamic and echocardiographic data were collected at baseline in 165 patients undergoing balloon aortic valvuloplasty and examined for their ability to predict long-term outcome. RESULTS: The median duration follow-up was 3.9 years (range 1 to 6). Ninety-nine percent follow-up was achieved. During this 6-year period, 152 patients (93%) died or underwent aortic valve replacement, and 99 (60%) died of cardiac-related causes. The probability of event-free survival (freedom from death, aortic valve replacement or repeat balloon aortic valvuloplasty) 1, 2 and 3 years after valvuloplasty was 40%, 19% and 6%, respectively. In contrast, the probability of survival 3 years after balloon aortic valvuloplasty in a subset of 42 patients who underwent subsequent aortic valve replacement was 84%. Survival after aortic valvuloplasty was poor regardless of the presenting symptom, but patients with New York Heart Association functional class IV congestive heart failure had events earliest. Univariable predictors of decreased event-free survival were younger age, advanced congestive heart failure symptoms, lower ejection fraction, elevated left ventricular end-diastolic pressure, presence of coronary artery disease and increased left ventricular internal diastolic diameter. Stepwise multivariable logistic regression analysis found that only younger age and a lower left ventricular ejection fraction contributed independent adverse prognostic information (chi-square 14.89, p = 0.0006). CONCLUSIONS: Long-term event-free and actuarial survival after balloon aortic valvuloplasty is dismal and resembles the natural history of untreated aortic stenosis. Aortic valve replacement may be performed in selected subjects with good results. However, the prognosis for the remainder of patients who are not candidates for aortic valve replacement is particularly poor.

Aged↗
PubMed1994

Indications for and applications of the Gianturco-Roubin coronary stent.

The Gianturco-Roubin coronary stent is approved for and effective in the management of acute or threatened closure after unsuccessful coronary intervention. Factors critical to successful stenting include patient and lesion selection, preprocedure identification of patients in potential need of stenting, selection of stent-compatible ancillary equipment, appropriate antiplatelet and anticoagulant therapy, postdeployment stent dilatation, and careful sizing of stents. Further refinements of technique and adjunctive drug therapy should continue to improve results and avoid acute complications. Published clinical experience and potential future applications are discussed.

Angioplasty, Balloon, Coronary↗
PubMed1993

In vivo validation of compensatory enlargement of atherosclerotic coronary arteries.

Necropsy examinations and epicardial ultrasound studies have suggested that atherosclerotic coronary arteries undergo compensatory enlargement. This increase in vessel size may be an important mechanism for maintaining myocardial blood flow. It also is of fundamental importance in the angiographic study of coronary disease progression and regression. The purpose of this study was to determine, using intracoronary ultrasound, whether coronary arteries undergo adaptive expansion in vivo. Forty-four consecutive patients were studied (30 men, 14 women; mean age 56 +/- 10 years). Eighty intravascular ultrasound images were analyzed (32 left main, 23 left anterior descending and 25 right coronary arteries). Internal elastic lamina area, a measure of overall vessel size increased as plaque area expanded (r = 0.57, p = 0.0001, SEE = 5.5 mm2). When the left main, left anterior descending and right coronary arteries were examined individually, there continued to be as great or greater positive correlation between internal elastic lamina and plaque area (left anterior descending: r = 0.75, p = 0.0001; right coronary arteries: r = 0.63, p = 0.0007; left main: r = 0.56, p = 0.0009), implying that each of the vessels and all in aggregate underwent adaptive enlargement. When only those vessels with < 30% area stenosis were examined, internal elastic lamina correlated well with plaque area (r = 0.79, and p = 0.0001), and for each 1 mm2 increase in plaque area, internal elastic lamina increased 2.7 mm2. This suggests that arterial enlargement may overcompensate for early atherosclerotic lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

Adaptation, Physiological↗
PubMed1993

Unrecognized left main coronary artery disease in patients undergoing interventional procedures.

Selective, coronary arteriographic, catheter-based, intravascular ultrasound images were obtained to determine the presence and extent of angiographically undetected or underestimated left main (LM) coronary arterial narrowing in patients receiving coronary interventional therapy. Coronary arteriograms were determined to be either normal or abnormal by visual inspection. Abnormal arteriograms were digitized and quantitated using a semiautomated edge-detection algorithm. Thirty-eight patients receiving percutaneous treatment of stenoses in the left coronary artery system were studied. Optimal LM coronary angiograms were obtained in 2 views, and intravascular ultrasound images were obtained after the coronary interventional procedure. Intravascular ultrasound detected plaque in 24 of 27 angiographically normal LM arteries (89%), whereas narrowing was observed in 11 of 11 angiographically abnormal LM arteries (100%). Eight of 38 patients (21%) had > 40% area stenosis by intravascular ultrasound. In patients with angiographic disease, there was no correlation between quantitative angiographic and ultrasound percent area stenosis (r = 0.12; p = 0.72; SEE 19%). The median plaque area was not different between angiographically normal (0.05 cm2; 0.03, 0.08 [25th, 75th percentile]) and abnormal (0.06 cm2; 0.03, 0.1) patients. The median percent area stenosis in arteriographically normal subjects (26%; 14, 32%) was less than that in abnormal ones (37%; 20, 46%) (p = 0.03). Unrecognized LM disease is widespread and often underestimated in patients with normal LM angiograms undergoing interventional procedures. Plaque area is similar for angiographically normal and insignificantly abnormal vessels. This study suggests that intravascular ultrasound overcomes the limitations of silhouette imaging and can be a clinically useful, adjunctive method to evaluate LM coronary artery disease.

Algorithms↗
PubMed1992

Left ventricular filling and ventricular diastolic performance after percutaneous balloon mitral valvotomy.

The time course of left ventricular (LV) filling and LV diastolic performance were examined in 27 consecutive patients in sinus rhythm before and acutely after balloon mitral valvotomy (BMV). The mitral valve area acutely increased from 1.1 +/- 0.3 to 2.1 +/- 0.8 cm2. Simultaneous pressure-volume data were obtained using digital subtraction left ventriculography and LV micromanometer pressure before and 10 minutes after BMV. The time constant of LV isovolumic relaxation was unchanged after BMV (50 +/- 10 ms before BMV vs 47 +/- 13 ms after BMV). In addition, values before and after BMV for LV end-diastolic volume (123 +/- 29 vs 125 +/- 36 ml), end-diastolic pressure (11 +/- 4 vs 12 +/- 4 mm Hg) and diastolic filling time (337 +/- 126 vs 338 +/- 152 ms) were not altered by the procedure. After BMV the peak diastolic filling rate (403 +/- 143 vs 469 +/- 302 ml/s) was maintained despite a 36% reduction in left atrial filling pressure. There was a trend toward earlier occurrence of the peak filling rate (196 +/- 127 vs 146 +/- 148 ms, p = 0.08). The percentage of diastolic filling in the first third of diastole, however, was similar (42 +/- 9 vs 48 +/- 16%) before and after the procedure. Thus, the time course of LV filling is not significantly altered acutely after BMV, but is maintained at reduced left atrial filling pressure. Neither LV relaxation or LV chamber compliance are altered acutely after BMV.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Quantitative and qualitative coronary angiographic analysis: review of methods, utility, and limitations.

Coronary angiography continues to be the pivotal study in the diagnosis and treatment of ischemic cardiac disease. Although angiographic equipment and imaging techniques have advanced over the past three decades, the analysis of coronary angiograms, by visual estimated percent diameter stenosis, has remained unchanged in most clinical catheterization laboratories. Rapid, computerized angiographic analysis systems are now available that remedy the inherent imprecision and inaccuracies plaguing visual coronary analysis. Despite its advantages, successful QCA is quite dependent on meticulous attention to radiographic and angiographic technique, even more so than with visual analysis. Although the available QCA systems can reproducibly and accurately define the site and degree of coronary stenosis, they cannot routinely determine whether an obstruction is flow limiting. Several methods, some based on extrapolations of quantitative measures alone, and others based on digital subtraction angiography, have been developed to determine the physiologic impact of a given coronary lesion. Recent observations have demonstrated, however, that even if the physiologic consequences of an obstruction are known, the prognosis of the lesion over time cannot be predicted. The qualitative, morphologic characteristics of a lesion are as, or more, important than the quantitative lesion attributes in determining an atheroma's behavior and stability, and hence, qualitative descriptors should be incorporated into QCA analyses. Although not currently available, future QCA systems will provide, by automated analysis, reproducible and accurate measures of absolute obstruction, physiologic data describing the flow limiting characteristics of a lesion, and qualitative, morphologic lesion descriptors. Implementation of these systems should provide more consistent and accurate prognostic and pathophysiologic information, thereby helping to refine and more effectively direct therapeutic interventions in coronary artery disease.

Algorithms↗
PubMed1992

Use of balloon occlusion to improve visualization of anomalous pulmonary venous return in an adult with cor triatriatum.

Cor triatriatum, although rare in adults, is often associated with anomalous pulmonary venous return. Accurate diagnosis of the pulmonary venous return and its anatomic connections is essential in planning proper surgical correction. This case illustrates the advantage of selective pulmonary artery angiography in obtaining accurate detail of the pulmonary venous anatomy from digital subtraction levophase images. Selective right and left pulmonary angiography was performed using a balloon catheter to simultaneously occlude the opposite pulmonary artery. This technique was well tolerated and greatly enhanced visualization of the anomalous pulmonary venous connections, allowing proper planning for corrective surgery.

Angiography, Digital Subtraction↗
PubMed1992

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 Prinzmetal's 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.

Angina Pectoris, Variant↗
PubMed1992

Renal artery stenosis: prevalence and associated risk factors in patients undergoing routine cardiac catheterization.

The purposes of this study were to determine the prevalence of angiographically significant renal artery stenosis in a patient population referred for diagnostic cardiac catheterization and to develop a model that predicts the highest-risk subset of patients who have significant renal artery narrowing. A prospective validation cohort study was undertaken in a referral-based university hospital. After left ventriculography, abdominal aortography was performed to screen for the presence of renal artery disease. A convenience sample of 1,302 of 1,651 consecutive patients undergoing diagnostic cardiac catheterization were enrolled in the study. Of the 1,302 abdominal aortograms performed, 1,235 (95%) were deemed of adequate quality for the evaluation of renal artery anatomy. Renal artery disease was identified in 30% of the patients. Insignificant renal artery stenosis was found in 187 (15%) and significant (greater than or equal to 50% diameter narrowing) stenosis was found in 188 (15%). Significant unilateral disease was present in 11%, and bilateral disease was present in 4%. By univariable and multivariable logistic regression analysis, the association of both clinically and catheterization-derived variables with renal artery disease was assessed. Multivariable predictors included age, severity of coronary artery disease, congestive heart failure, female gender, and peripheral vascular disease. Hypertension was not an associated variable. These data reveal the previously undetected high prevalence of renal artery disease in patients undergoing cardiac catheterization and provide clinical and angiographic features that assist in predicting its presence.

Aged↗
PubMed1991

Determinants of one-year outcome from balloon aortic valvuloplasty.

Balloon aortic valvuloplasty (BAV) has been a therapeutic alternative treatment for severe symptomatic aortic stenosis. Previous studies have been unable to predict 1-year outcome because of limited acute and follow-up clinical, invasive and echocardiographic data. The purpose of this study was to predict long-term outcome based on comprehensive data obtained at the time of valvuloplasty and at 3 and 6 months after the procedure. Of 170 consecutive patients undergoing BAV, 108 (mean age 78 years) were at least 1 year from their procedure. Prospective clinical, micromanometer hemodynamic, digital ventriculographic and echocardiographic/Doppler data were collected at baseline and immediately after the procedure. Echocardiographic data were also obtained at 3 and 6 months. With use of Cox model analysis, major events (defined as cardiac death [n = 30], aortic valve replacement [n = 21] or repeat BAV [n = 13]) were predicted by advanced age, baseline heart failure class, and baseline echocardiographic-determined diastolic left ventricular diameter. Only baseline left ventricular ejection fraction proved to be a significant predictor of cardiac death (p = 0.002) in a multivariate model. Absolute values after BAV (stroke work, first derivative of left ventricular pressure, valve area, end-systolic volume, Fick cardiac output, transvalvular gradient) and acute changes measured by catheterization or echocardiography did not provide additional predictive information over that of post procedure ejection fraction. Similarly, echocardiographic valve area and transvalvular gradient at 3 months added no further prognostic data. With an ejection fraction greater than or equal to 45% (n = 63), cardiac survival at 1 year was 80%, irrespective of age, sex, congestive heart failure class or severity of coronary artery disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

Amrinone during porcine intraperitoneal sepsis.

Seven Yucatan minipigs with chronic, severe intraperitoneal sepsis were given amrinone i.v. (loading dose of 0.75 mg/kg, followed by continuous infusion of 10, 20, 40, and 80 micrograms/kg/min) during the hyperdynamic phase of sepsis. Hemodynamic variables and oxygen utilization, delivery, and extraction were recorded throughout the study. Pulmonary capillary wedge pressure was kept constant to ensure a fixed ventricular filling pressure. Intravenous amrinone modestly augmented cardiac index without altering heart rate. Mean systemic and pulmonary arterial pressures decreased. Systemic and pulmonary vascular resistance fell significantly (P less than 0.05). Amrinone did not significantly alter oxygen utilization or oxygen extraction, although oxygen delivery increased (P less than .05). During the hyperdynamic phase of sepsis in this animal model, amrinone elicits vasodilatation with a modest improvement in stroke volume index. Consequently, cardiac output and oxygen delivery increased modestly. Because of its vasodilating properties and small salutary effects, amrinone is not an optimal first-line medication for hemodynamic stabilization during hyperdynamic sepsis.

Amrinone↗
PubMed1989

Modification of protein kinase C (PKC) activity and diacylglycerol (DAG) accumulation in hepatocytes in continuous endotoxemia.

On the basis of our work, the status of PKC-mediated signal transduction in hepatocytes in chronic endotoxemia can be summarized as follows: 1. Vasopressin (10(-8) M)-induced DAG accumulation is delayed and reduced by 50%, as compared with the response of cells of saline-infused rats. 2. Under basal conditions, total PKC activity (cytosol + pellet) is elevated due to a tendency for higher cytosolic fractional activity. 3. Both TPA- and hormonally-induced (in response to VP and PE) translocation are impaired. 4. Quantitative receptor autoradiography reveals a selective decrease in [3H-PDBu] binding sites in hepatic membranes. We conclude that modulation in endotoxemia of the DAG signal elicited by VP stimulation in hepatocytes could lead to altered transmembrane control of PKC-mediated protein phosphorylation, thereby contributing to the mechanism of impairments in the regulation of cellular metabolism.

Animals↗
PubMed1985

Combining left ventricular systolic time intervals and M-mode echocardiography in the evaluation of primary pulmonary hypertension in women.

Eight patients with primary pulmonary hypertension underwent systolic time intervals, M-mode echocardiography, and direct hemodynamic studies in order to determine the correlation between noninvasive parameters and hemodynamic variables and to evaluate the utility of these noninvasive studies in primary pulmonary hypertension. The ratio of the pre-ejection period to left ventricular ejection time (PEP/LVET) of the systolic time intervals was abnormally increased (greater than 0.42) for each subject; the increase in the PEP/LVET was secondary to a shortening of the left ventricular ejection time in four patients, prolongation of the pre-ejection period in one, or a combination of such, noted in three patients. In contrast, echocardiographic parameters of left ventricular function, specifically percent change in the minor axis of the left ventricle with systole, velocity of circumferential fiber shortening, and ejection fraction, were normal. In addition, a very good correlation was noted between PEP/LVET and total pulmonary resistance (r value = -0.89, p less than 0.05), while the echocardiographic parameters correlated well with stroke volume and cardiac output (r values ranged from 0.68 to 0.72, p less than 0.05). These results indicate that in primary pulmonary hypertension, the performance of both systolic time intervals and M-mode echocardiography noninvasively provides useful information concerning the hemodynamic status of these patients. Systolic time intervals provide an estimation of overall cardiac-cardiovascular performance, rather than left ventricular function alone, which in turn, is validly examined by M-mode echocardiography.

Adult↗