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B J Rubal

Publications and source records attributed to B J Rubal.

At least 19 recordsLinked to original sources
PubMed2001

Comparison of low-volume versus standard-volume left ventriculography.

Left ventriculography provides useful information about cardiac function, wall motion, and mitral regurgitation (MR). However, standard volumes of contrast agent frequently are associated with ventricular ectopy. This study compares the use of low-volume (Low-vol) ventriculography to standard volume (Std-vol) ventriculography. Left ventricular (LV) ejection fraction (EF), changes in LV end-diastolic pressure (LVEDP), the incidence of ectopy, and > 2+ MR were prospectively determined from the random order use of standard (15 mL/ second for 3 sec) and low-volume (15 mL/sec for 1 sec) contrast agents in 102 patients. Each patient served as his or her own control. Twenty-seven percent of the 204 ventriculograms were not interpretable due to ectopy. Ectopy > or = 3 beats was more common with Std-vol angiograms (41% vs. 14%, P < 0.001). Post-injection LVEDP increased from baseline after both Std-vol and Low-vol injections (P < 0.001). In patients for whom both angiograms could be interpreted (n = 58), no differences were noted between planimetered EFs (Low-vol = 61 +/- 20% vs. Std-vol = 62 +/- 20%, with r = 0.87; P < 0.001). A Bland-Altman test of agreement indicated a mean difference +/- 95% CI = -2 +/- 19%. Low-volume ventriculography reduces contrast load and ectopy while providing similar estimates of EF compared with standard volumes.

Adult↗
PubMed2001

Assessing myocardial viability using the coronary flow response to intravenous dobutamine infusion in recent myocardial infarction.

Coronary flow response to low-dose (5 and 10 micrograms/kg/min) dobutamine infusion was used to assess myocardial viability at the time of cardiac catheterization in 13 patients (age, 60 +/- 11 years) with recent myocardial infarction. Echocardiographic improvement in regional wall motion performed 4 to 6 weeks after discharge was used as the marker for viability. Viable patients demonstrated a 2-fold increase in flow from baseline (p < 0.001) during intravenous infusion. In contrast, patients without viability demonstrated no increase in flow. The coronary flow response to dobutamine measured at the time of catheterization shows promise in identifying viable myocardium in postinfarction patients.

Adult↗
PubMed2001

Five-year experience with implantation and follow-up of transvenous implantable cardioverter defibrillators: placing postimplant defibrillation threshold testing in perspective.

BACKGROUND: The rapid technological advancement in transvenous implantable cardioverter defibrillators (ICDs) has resulted in heterogeneous and often controversial approaches to follow-up procedures. The efficacy of postimplantation defibrillation threshold (DFT) testing with new-generation biphasic ICDs is unknown. OBJECTIVE: In this retrospective study, predischarge and postdischarge DFT protocols were compared to evaluate their safety and effect on adverse clinical events. METHODS: The study population consisted of 89 patients with 92 ICDs and 103 endovascular lead systems. Forty-four patients had DFT tests during implant and the predischarge period. Thirty patients had DFT tests during implant and the postdischarge period. Sixteen patients had only implant DFT data available. The follow-up period ranged from 3 days to 5.6 years. RESULTS: Ninety-nine percent of patients had successful implants. Postimplant DFT tests detected potential problems in only 1% of asymptomatic patients. Thirty-six percent of patients with normal predischarge DFT tests had adverse clinical events compared with 18% in the postdischarge group. Patients with postimplant DFTs > 25 joules (J) and safety margins > or = 10 J had a lower incidence of adverse clinical events (p = 0.03) compared with those with safety margins < 10 J. An 11% malfunction rate was observed in ICD leads during the follow-up period. CONCLUSIONS: DFT testing after implant is safe; however, routine postimplant DFT testing has limited value in assessing abnormalities in patients with the current generation of biphasic transvenous ICD devices. A 10-J safety margin was associated with a lower incidence of adverse clinical events in patients with DFTs > 25 J. Endovascular lead failure remains a significant problem with ICD systems requiring vigilant follow-up.

Aged↗
PubMed2000

Ascending aortic atheroma assessed intraoperatively by epiaortic and transesophageal echocardiography.

BACKGROUND: The presence of ascending aortic atheroma is a known risk for systemic emboli or early saphenous vein graft failure if unrecognized at the time of cardiopulmonary bypass. METHODS: This study prospectively compared intraoperative omniplane transesophageal echocardiography (TEE) and epiaortic ultrasound (EAU) images in 22 patients (6 women, 16 men, age 66 +/- 8 years) before surgical manipulation of the ascending aorta. Atheroma lesion severity was scored: 1 = normal, 2 = nonprotruding intimal thickening (> 2 mm), 3 = atheroma less than 4 mm +/- Ca++, 4 = atheroma greater than or equal to 4 mm +/- Ca++, and 5 = any size mobile or ulcerated lesion +/- Ca++. The ascending aorta between the aortic valve and innominate artery was divided into proximal, middle, and distal segments. A total of 66 segments were evaluated. RESULTS: Although the overall agreement of scores between procedures was 75.8%, significantly more lesions were identified by EAU (15) than by TEE (5) (p < 0.03). TEE failed to identify lesions in the middle and distal segments of the aorta with a score of more than 3. CONCLUSIONS: Although atheromatous lesions were identified in the ascending aorta by both ultrasound modalities, the results suggest that intraoperative EAU may have an advantage over TEE for surgeons assessing target sites for surgical procedures involving the ascending aorta.

Aged↗
PubMed2000

Effects of intracoronary nicardipine, diltiazem and verapamil on coronary blood flow.

BACKGROUND: Intracoronary (IC) calcium channel blockers (CCB) such as diltiazem and verapamil are frequently utilized during percutaneous coronary interventions to maximize coronary blood flow. Their use, however, may be limited by systemic side effects such as hypotension and bradyarrhythmias. The vasoselective dihydropyridines, such as nicardipine, may be more effective at increasing coronary blood flow with fewer systemic side effects. This study compares the effects of nicardipine, diltiazem and verapamil on coronary blood flow, heart rate and blood pressure. METHODS: IC nicardipine (200 mcg), diltiazem (1 mg) and verapamil (200 mcg) were serially administered in a randomized, double-blinded fashion in minimally diseased (< 30% stenosis) left anterior descending or left circumflex arteries in nine patients. Epicardial coronary artery diameter (ECAD) was determined by quantitative coronary angiography and coronary blood flow velocity (CBFV) was measured by Doppler Flowire in each patient before and after each medication. RESULTS: Nicardipine significantly increased CBFV (p < 0.05) and had a longer duration of effect (p < 0.05), but had no difference in ECAD compared with diltiazem and verapamil. No differences were noted between CCB in changes in heart rate or mean arterial blood pressure. However, two patients had transient episodes of Type I second degree AV block after receiving diltiazem. CONCLUSION: When compared with diltiazem and verapamil, nicardipine appears to offer more potent and more prolonged vasodilatation with less risk of serious systemic side effects. Future studies are needed to assess the efficacy of IC nicardipine in patients with no-reflow.

Aged↗
PubMed1998

Variation of flow propagation velocity with age.

Flow propagation velocity is a new color Doppler M-mode measurement of left ventricular filling characteristics. This study was designed to establish normal values for this measurement in healthy individuals and to compare these findings with pulsed Doppler transmitral velocities. Complete M-mode, two-dimensional, and Doppler echocardiographic studies were performed on 64 volunteers between 21 and 79 years of age. Significant negative correlations (p < 0.001) with age were noted for flow propagation velocity (r = -0.59), peak early diastolic filling velocity (r = -0.65), and peak early diastolic filling/peak atrial filling ratio (r = -0.80). Positive correlations (p < 0.001) with age were observed for peak atrial filling velocity (r = 0.50) and atrial filling velocity integral (r = 0.71). Flow propagation velocity decreased by 44% between the youngest and oldest age groups. We conclude that flow propagation velocity is influenced by age and that it compares favorably with transmitral Doppler indices of left ventricular filling in this regard. These age-related alterations are present in healthy individuals, in the absence of any apparent cardiovascular disease.

Adult↗
PubMed1997

Doppler echocardiography in cardiac transplant patients: allograft rejection and its relationship to diastolic function.

Right ventricular endomyocardial biopsy has been the traditional gold standard for determining cardiac transplant rejection. Although endomyocardial biopsy has proved useful in guiding rejection therapy, this procedure is not without risk. The objective of the present study was to determine whether a noninvasive method for assessing cardiac diastolic function would be of value in predicting biopsy scores. Doppler echocardiographic indices of left ventricular function were compared with biopsy scores in 43 studies from 23 patients (age 50 +/- 8 years). The average time from transplant to echocardiographic study was 1.5 years. Standard clinical indices of diastolic function failed to predict biopsy results. The A-Ar interval, evaluated in 36 studies, was found to significantly decrease (p < 0.003) with increasing biopsy scores. Preliminary results suggest that this echocardiographic parameter may prove useful in predicting biopsy results.

Biopsy, Needle↗
PubMed1997

Rehabilitation following redo revascularization and repaired sternotomy.

Currently there are no guidelines for exercise prescription for cardiac patients with repaired sternotomy. This study reports good results in a 63-yr-old patient with prolonged course of hospitalization following mediastinitis and discusses considerations required for safe participation in competitive sports.

Coronary Artery Bypass↗
PubMed1997

Serum creatine kinase kinetics after endomyocardial biopsy in cardiac transplant patients.

The objective of this study was to define the changes in serum creatine kinase (CK) and creatine kinase-MB isoenzyme (CK-MB) activities following endomyocardial biopsy. Ten cardiac transplant recipients underwent routine surveillance endomyocardial biopsy via the right internal jugular vein with single-use disposable bioptomes. Serum CK and CK-MB levels were measured at baseline and post-biopsy at 15, 30, and 45 minutes, 1, 1.5, 2, 4, 6, 8, 12, 16, 20, and 24 hours. There was no significant increase in serum total CK after biopsy. No measurable change in CK-MB was observed in 40% of patients. CK-MB increased significantly in the remaining patients (N = 6) at 30 minutes (p < 0.05), and continued to rise to a peak at 4 hours post-biopsy, after which CK-MB gradually decreased to baseline. However, the increase in CK-MB did not meet criteria for the diagnosis of myocardial necrosis, hence should not be confused with the change in CK-MB occurring with myocardial infarction. These findings suggest that serum CK-MB activity is useful in the differential diagnosis of chest pain in cardiac transplant patients in the setting of recent biopsy.

Adult↗
PubMed1997

Myocardial ischemia and stunning induced by topical intranasal phenylephrine pledgets.

This case study describes myocardial ischemia and stunning after the topical application of phenylephrine-soaked pledgets (0.25%) in a 63-year-old female undergoing elective endoscopic sinus surgery. The patient had no previous history of cardiovascular disease or illicit drug use. Transient myocardial ischemia was associated with acute hypertension, chest pain, and S-T segment changes 4 minutes after pledget placement. Angiography revealed normal coronary blood flow and severe left ventricular systolic and diastolic dysfunction. Follow-up echocardiography demonstrated improved left ventricular function within 1 week and total resolution of dysfunction by 4 weeks after ischemia.

Administration, Intranasal↗
PubMed1996

Bayesian analysis of noninvasive versus oral temperature measurements to determine hypothermia in postoperative patients.

Measurement of body temperature in the postanesthesia care unit (PACU) is an important parameter in patient management. Failure to reach minimal acceptable body temperature standards has been associated with physiologic derangements, the application of additional therapy, and prolonged PACU stays. Newer methods to monitor temperature introduced into the PACU have been touted to be adequate for detecting clinically significant changes in temperature. In this study, skin core-temperature-corrected liquid crystal thermography (LCT), axillary (AT) electronic, and infrared tympanic membrane (ITT) temperatures were compared with oral thermistor thermometry (OT) in 205 PACU patients. Regression analysis suggests that when compared with the oral method, ITT tends to overestimate and AT and LCT tend to underestimate oral temperatures. Mean temperatures obtained by LCT (35.5 +/- 1.0 degrees C), AT (35.1 +/- 0.9 degrees C), and ITT (36.3 +/- 0.8 degrees C) differed significantly from OT (36.0 +/- 0.7 degrees C) mean temperatures. We applied Bayesian analysis to assess the sensitivity and specificity of each method, using a hypothermia reference of < 36 degrees C. Results suggest that the definition of hypothermia may depend on the modality used to assess body temperature in the PACU.

Adult↗
PubMed1995

Effects of atenolol on rest and exercise hemodynamics in patients with mitral stenosis.

Beta-blocker therapy remains controversial in patients with mitral stenosis. In this randomized, double-blind, crossover, placebo-controlled study, the effects of atenolol (50 and 100 mg/day) were assessed in 15 patients (aged 46 +/- 11 years) with mitral stenosis (mean valve area 1.0 +/- 0.4 cm2; New York Heart Association class II or III) at rest and during upright bicycle ergometry. Doppler echocardiography was used to compare heart rate, cardiac and stroke volume indexes, diastolic filling period, and peak and mean transmitral gradients; a metabolic cart was used to obtain maximal oxygen consumption, carbon dioxide production, and anaerobic threshold. Beta-blocking therapy did not improve exercise time, external work, maximal oxygen consumption rate, or anaerobic threshold. Compared with placebo, maximal oxygen consumption rate and cardiac index decreased (p < 0.05) > 11% and > 20%, respectively, with atenolol at peak exercise. Although heart rate was reduced > 20% and diastolic filling period prolonged > 40% by atenolol at rest and exercise (p < 0.05), stroke volume index changed little compared with placebo. The data suggest that despite lower transvalvular pressure gradients, little benefit in exercise performance is achieved with beta-blocker therapy in patients with severe mitral stenosis.

Adult↗
PubMed1995

Effects of chronic beta-blockade on rest and exercise hemodynamics in mitral stenosis.

beta-blocker therapy for mitral stenosis is controversial. This study compares right and left heart hemodynamics at rest and supine submaximal exercise in patients (n = 7) receiving chronic beta-antagonists with untreated patients (n = 17) matched for age (mean +/- SD = 51 +/- 12 years) and valve area (0.7 +/- 0.2 cm2/m2). Little benefit was observed with treatment at rest. Although pulmonary capillary wedge pressures (PCWP) were lower during exercise in the beta-blocker group (22 +/- 4 vs. 31 +/- 9 mmHg; P < 0.05), exercise performance was not enhanced and cardiac output response during exercise was reduced (control = 41% increase vs. 12% for beta-blockade). PCWP rose rapidly when diastolic filling periods were < 300 msec in both groups. Pulmonary capillary wedge pressure was found to be a nonlinear functions (P < 0.001) of diastolic filling period (PCWP = 15.9 + 5.84 x 10(5)/dfp2). These data suggest that there is a critical heart rate in patients with mitral stenosis above which hemodynamic compromise rapidly occurs.

Adrenergic beta-Antagonists↗
PubMed1995

High balloon dilatation pressures in percutaneous transluminal coronary angioplasty are not associated with higher rate of significant complications.

To examine the results of high balloon dilatation pressures during percutaneous transluminal coronary angioplasty (PTCA), we retrospectively reviewed 482 angioplasty cases from our institution and divided them into three groups by the peak inflation pressure used during the procedure. Group one was defined by inflation pressures of 1-6 atmospheres (atm), group two by 7-12 atm, and group three by 13-20 atm. There were 166 patients in group 1 (34.4%), 235 in group 2 (48.8%), and 81 (16.8%) in group 3. The success rates were not statistically different; 90% in group 1, 96% in group 2, and 95% in group 3. Large dissections occurred in 27 patients in group 1 (16.3%), 19 in group 2 (8.1%), and 4 (4.9%) in group 3 (P > 0.006). There were no differences in the rates of death (1.2% vs. 0.9% vs. 1.2%), myocardial infarction (3.0% vs. 1.3% vs 3.7%), or in-hospital CABG (3.0% vs. 1.7% vs. 1.2%) in groups 1, 2, and 3, respectively. Six-mo target vessel revascularization rates also were not different: 19% vs. 13% vs. 18%. In summary, selectively using high balloon pressures during PTCA does not result in increased complications.

Angioplasty, Balloon, Coronary↗
PubMed1995

Time-frequency analysis of ECG for late potentials in sudden cardiac death survivors and post-myocardial infarction patients.

Late potentials (LPs) are harbingers of sudden cardiac death (SCD) for certain patient populations, including SCD survivors and patients post myocardial infarction. This retrospective study examined the sensitivity and specificity of time-frequency distributions (TFDs) in detecting late potentials in 90 patients using time-domain signal average ECG criteria as a standard for comparison. Three time-domain criteria were employed: QRS duration > 114 msec; LAS > 30 msec; and RMS40 < 20 microV. Time domain criteria were compared with TFD results derived using the binomial transform. TFDs were considered positive if small magnitude (-30 dB) signals > 40 Hz were present 114 msec after the onset of the QRS complex. Results from the binomial transform are comparable to those from the SAECG method (sensitivity = 92.0-100%, specificity = 78-92%).

Adult↗
PubMed1995

S2 triggered gated blood pool imaging for assessment of diastole.

Evaluation of diastolic function using ECG-Gated Blood Pool (EGBP) imaging is limited by inaccurate reproduction of the ventricular volume curve during diastole. Gating to an end-systolic event may reduce the influence of heart period variability, improving the fidelity of this curve during diastole. Heart Sound-Gated Blood Pool (HSGBP) imaging was employed to initiate acquisition at the Second Heart Sound (S2) using a previously reported Heart Sound Gate, and an accelerometer. Seven patients underwent EGBP imaging at 24 and 56 frames per second (fps), and HSGBP imaging at 24 fps. Utilizing EGBP imaging a mean ejection fraction (EF) of 54% was obtained at 24 fps, with HSGBP imaging yielding 53%. EF obtained by HSGBP and EGBP imaging correlated closely (r = 0.96, p < .002). The mean EF during 56 fps EGBP imaging was greater at 67%, consistent with previous reports. Additionally, peak filling rates by HSGBP and EGBP imaging correlated well (r = 0.95, p < .02). The fidelity of the diastolic ventricular volume curves for HSGBP and EGBP methods were comparable in four patients, and superior with HSGBP imaging in four patients. In conclusion, HSGP imaging is a feasible method for acquisition of the ventricular volume curve, and may assess diastolic function indices with greater accuracy. Further investigation of this application is warranted.

Diastole↗
PubMed1994

Effect of magnesium sulfate on ventricular rate control in atrial fibrillation.

STUDY OBJECTIVES: The objectives of this study were to assess the efficacy of parenteral magnesium sulfate (MgSO4), digoxin, and combined MgSO4-digoxin therapies in acutely lowering ventricular rates in patients with newly recognized atrial fibrillation. DESIGN: A randomized, double-blinded, placebo-controlled clinical study. SETTING: US Army tertiary care facility. PARTICIPANTS: Fifteen adults (mean age, 62 +/- 19 years) presenting with newly recognized atrial fibrillation and rapid ventricular rate (more than 99). INTERVENTIONS: Patients were given an initial parenteral MgSO4 bolus with continuous infusion or placebo. After 30 minutes, all patients were given 0.5 mg IV digoxin and followed for 3.5 hours. MEASUREMENTS AND MAIN RESULTS: Ventricular rates were obtained at baseline, every 5 minutes for the first 30 minutes, and then every 30 minutes for 3.5 hours. At 5 minutes, ventricular rates decreased 16 +/- 7% (P < .02) with MgSO4; this was comparable with rate control with digoxin (18 +/- 9%) at 4 hours. Rate control tended (26 +/- 7%) to improve with combined therapy. CONCLUSION: Parenteral MgSO4 may be useful in the acute management of rapid ventricular rates in patients with atrial fibrillation.

Aged↗