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Biomedical subjects

A E Moreyra

Publications and source records attributed to A E Moreyra.

At least 19 recordsLinked to original sources
PubMed2001

Comparison of comfort and local complications after cardiac catheterization.

The purpose of this study was to compare the effects of 4 hours of bed rest versus 6 hours of bed rest on patients' safety, comfort, and satisfaction levels. Using a quasi-experimental design, the authors studied 118 left-heart catheterization patients who were randomly assigned to 4 hours or 6 hours of bed rest. Among the study participants, only 1 in the 6-hour group had significant bleeding. There were no complications in the 4-hour group. There were no statistically significant differences between the two groups on any of the other study variables. Given the lack of significant complications for the 4-hour group and similar comfort levels for both study groups, these findings suggest the feasibility of reducing the standard period of postcatheterization bed rest from 6 hours to 4 hours, thereby possibly lowering the cost of the outpatient procedure.

Cardiac Catheterization↗
PubMed2000

Coronary rotational atherectomy via transradial approach: a study using radial artery intravascular ultrasound.

The use of coronary rotational atherectomy via radial artery (RA) has been limited because of the large diameter of guiding catheters. We studied the feasibility of this approach by sizing the RA by intravascular ultrasound (IVUS) and using 7 Fr (2.31 mm) guiding catheters. Seventeen transradial percutaneous transluminal coronary rotational atherectomy (PTCRA) procedures were performed in 16 patients, mean age 62 +/- 12 years, for a total of 19 vessels treated. The mean RA diameter was 2.9 +/- 0.36 mm and the mean reference diameter of the treated coronary vessels was 2.7 +/- 0.45 mm. The mean coronary percent stenosis was 74% +/- 10%, the mean minimum lumen diameter was 0.76 +/- 0.35 mm, and the mean lesion length was 16 +/- 19 mm. Ten vessels were treated with rotational atherectomy alone, or with adjunctive high pressure balloon angioplasty, achieving an acute lumen gain of 0.8 +/- 0.4 mm (P = 0. 001). Nine arteries had stent implantation in addition to rotational atherectomy, resulting in an acute lumen gain of 2.4 +/- 0.5 mm (P = 0.001). The success rate was 94%. There were no vascular complications. Two patients had a non-Q myocardial infarction. In conclusion, transradial PTCRA when used in conjunction with IVUS of the RA is a safe and feasible procedure in selected cases. This may be an alternative approach of revascularization technique especially for patients with limited vascular access and for those who require early ambulation or early discharge from the hospital.

Aged↗
PubMed2000

Plexus between internal mammary graft and pulmonary vasculature after minimally invasive coronary surgery.

We report a complication associated with minimally invasive direct coronary artery bypass grafting surgery The patient suffered a nonfatal anterior myocardial infarction 1 day after he underwent minimally invasive bypass grafting using the internal mammary artery. Two months later, coronary arteriography revealed a fistulous connection between the left internal mammary graft and the left pulmonary vasculature. To our knowledge, this particular complication has not been reported following minimally invasive coronary surgery.

Arterio-Arterial Fistula↗
PubMed1999

Calcified splenic artery aneurysm discovered during coronary arteriography.

We present a case of calcified splenic artery aneurysm discovered during routine coronary angiography. Early awareness of these aneurysms is important since their rupture may cause serious complications. This case emphasizes the importance of attention to cardiac and extra-cardiac structures during coronary angiography.

Aged↗
PubMed1999

Improved detection of posterior myocardial wall ischemia with the 15-lead electrocardiogram.

BACKGROUND: A routine 12-lead electrocardiogram is commonly obtained to evaluate for possible acute myocardial infarction during the initial screening of patients with chest discomfort. Posterior myocardial infarction is commonly missed because it is not usually visible in the standard leads. In this study, we compared the sensitivity and specificity of posterior chest leads (V(7), V(8), and V(9)) and 12-lead electrocardiography in detecting posterior injury pattern during single-vessel percutaneous transluminal coronary angioplasty. METHODS AND RESULTS: Three posterior chest leads in addition to the routine 12-lead electrocardiogram were monitored simultaneously during single-vessel percutaneous transluminal coronary angioplasty of the right, circumflex, and left anterior descending coronary arteries in a total of 223 patients. Posterior injury patterns (95%) were detected mostly during circumflex coronary occlusion. Posterior leads were able to detect injury pattern in 49% (36 of 74) of patients, whereas the 12-lead electrocardiogram was able to detect only 32% (P <.04). When all 15 leads were used to detect all ST elevations, sensitivity increased to 57%, with a specificity of 98% for the circumflex coronary artery. If maximal ST depressions in leads V(2) to V(3) are considered to be from posterior myocardial injury, then the overall sensitivity is increased to 69%. CONCLUSIONS: Posterior leads significantly increased the detection of posterior injury pattern compared with the standard 12-lead electrocardiogram. Using all 15 leads significantly further improved the detection of circumflex coronary-related injury pattern over the standard 12-lead electrocardiogram.

Angioplasty, Balloon, Coronary↗
PubMed1998

Left internal mammary artery perforation during Swan-Ganz catheter insertion.

A wide spectrum of complications is associated with invasive hemodynamic monitoring. We report an unusual case of perforation of the left internal mammary artery that occurred during percutaneous insertion of a Swan-Ganz catheter using the subclavian vein approach. To the best of our knowledge, this complication has not been previously reported.

Aged↗
PubMed1998

Factors associated with atrial fibrillation in patients with mitral stenosis: a cardiac catheterization study.

Atrial fibrillation (AF) is frequently found in association with rheumatic mitral valve disease. To study the interrelation of factors contributing to the risk of AF in patients with mitral stenosis, we examined a cardiac catheterization database of a series of 314 patients. Patients with AF were older, 53.4 +/- 6.1 years versus 51.7 +/- 7.2 years (p = 0.03), and had a lower cardiac index, 2.3 +/- 0.6 L/min/m2 versus 2.6 +/- 0.7 L/min/m2 (p = 0.0002), than patients in sinus rhythm at catheterization. The mitral valve area was significantly smaller in patients with AF than in patients in sinus rhythm, 1.2 +/- 0.5 cm2 versus 1.6 +/- 0.7 cm2 (odds ratio 1.40/0.25 cm2 decrease; p = 0.0001) as was mitral valve index. The pressure-AF association with the highest statistical significance was seen with mean right atrial pressure, 10.6 +/- 4.9 mm Hg versus 7.6 +/- 3.8 mm Hg (odds ratio 2.24; p < 0.0001). Other variables with significant positive associations by univariate analysis were pulmonary artery wedge pressure, pulmonary artery mean pressure, and pulmonary resistance. When stepwise logistic multiple regression analysis was performed, the results indicated that both severity of mitral stenosis and increased right atrial pressure were independently associated with AF in this population with mitral stenosis. After adjustment was performed for these variables, age was not independently associated with AF.

Adult↗
PubMed1996

Effect of prolonged blood contact time on deposition of cellular and amorphous material on teflon-coated guidewires: a scanning electron microscopy study.

Prolonged contact of blood with guidewires and catheters has been implicated in leading to thromboembolic complications during cardiac catheterization. To study the effect of exposure time on blood product deposition on Teflon-coated guidewires, 35 patients undergoing routine coronary arteriography were randomly assigned to three time groups with exposure of the guidewire to blood of 3, 5, and 10 min, respectively. The exposed wires were examined by scanning electron microscopy, and the micrographs were graded by a pathologist "blinded" as to the exposure time. Deposition of cellular and amorphous material on the guidewire surface and interstices was graded using an arbitrary scale of 1-10 (1, least amount; 10, abundant amount of material). All patients received low-dose systemic administration of heparin (2,500 units) at the beginning of the procedure. The overall activated clotting time (ACT) was 147 +/- 39 sec (mean +/- SD) prior to heparin dose. The mean ACT after low-dose systemic heparin, measured at sheath removal immediately after exposure of the wire to blood had been completed, rose to 241 +/- 79 sec (P < 0.0001). The deposition of cellular and amorphous material on the surface and grooves of the wire was not significantly different at 3, 5, and 10 min. Thus, in this study, Teflon-coated guidewires showed no increase in cellular or amorphous deposits from 3 min to 10 min of blood-wire contact time in the presence of low-dose heparinization.

Aged↗
PubMed1996

Protective effect of nifedipine on myocardial stunning in isolated rabbit hearts: role of high energy phosphates stores.

The aim of the present study was to evaluate the effects of a single dose of nifedipine on myocardial stunning in isolated rabbit hearts. Hearts from rabbits pretreated with a single dose of 20 mg of nifedipine (NIF group) 1-4 h before isolation were compared to control hearts in their response to 15 min of global ischemia (37 degrees C) followed by 30 min of reperfusion. Both experimental groups showed similar baseline cardiac contractility. At the end of the reperfusion period in the control group, isovolumic left ventricular developed pressure (LVDP) and +dP/dtmax had stabilized at 45 +/- 2 and 48 +/- 2% of preischemic values respectively and in the NIF group LVDP stabilized at 63 +/- 6 and +dP/dtmax at 66 +/- 6% (P < 0.05 with respect to the control group). Left ventricular end diastolic pressure (LVEDP) values were significantly lower at the end of reperfusion in the NIF group compared to the controls (36.8 +/- 5.5 mmHg vs 53.4 +/- 3.9 mmHg, P < 0.05). The early impairment of the time constant of relaxation (tau) observed in control hearts was attenuated by pretreatment with nifedipine (control delta tau = 55 +/- 10 ms; NIF group delta tau = 29 +/- 5 ms, P < 0.05). Tissue ATP and creatine phosphate (CP) levels in the control group at the end of reperfusion were 6.9 +/- 0.7 and 8.7 +/- 0.7 mumol/g dry tissue, respectively; in the NIF group ATP and CP levels were significantly higher, 9.2 +/- 0.7 and 11.5 +/- 0.9 mumol/g dry tissue respectively (P < 0.05). Creatine kinase (CK) and lactate dehydrogenase (LDH) leakage during reperfusion were significantly higher in the control group (CK = 120 +/- 15 mU/ml and LDH = 60 +/- 8 mU/ml) compared to the NIF group (CK = 82 +/- 5 mU/ml and LDH = 41 +/- 2 mU/ml, P < 0.05). Our results demonstrate that pretreatment with a single oral dose (20 mg) of nifedipine attenuates systolic and diastolic functional alterations as well as the metabolic impairment associated with stunning in the isolated rabbit heart.

Adenosine Triphosphate↗
PubMed1996

Chronic nifedipine treatment diminishes cardiac inotropic response to nifedifine: functional upregulation of dihydropyridine receptors.

Chronic treatment with nifedipine induces up-regulation of functional active Ca2+ channels in cardiac muscle membranes. Adult male New Zealand White rabbits (NZW) were treated with nifedipine (20 mg/day) for 25 days. In isovolumic perfused hearts at constant coronary flow and heart rate (HR) the left ventricular developed pressure (LVDP) and its first derivative (dP/dt) were monitored. Basal contractility and contractility at different end-diastolic volumes (EDV) were higher in nifedipine-treated animals, with no changes in diastolic chamber stiffness. Dose response to nifedipine in pretreated animals showed less decrease in contractility than in controls [ED50 = 1.09 +/- 0.09 x 10-7 (control) and 1.55 +/- 0.17 x 10-7 M nifedipine (treated) (p < 0.05)]. Ca2+ channel density was assessed by specific binding at the dihydropyridine receptor with [methyl-3H]PN 200-110. In cardiac membranes, maximal binding capacity (Bmax) was 269 +/- 38 (n = 7, control) and 429 +/- 46 fmol/mg protein (n = 7, treated) (p < 0.05), without significant changes in dissociation constant. In addition, we noted no changes in dihydropyridine (DHP) binding sites in aortic membranes. Our results offer a possible explanation for the lack of decrease in contractility despite the persistent hypotensive effect in hypertensive patients during chronic treatment with nifedipine.

Animals↗
PubMed1996

Attenuation of myocardial stunning in isolated rat hearts by a 21-aminosteroid lazaroid (U74389G).

The purpose of this study was to evaluate the effects of reperfusion or in vivo pretreatment with a lipid peroxidation inhibitor, lazaroid (U74389G), on attenuating systolic and diastolic alterations occurring during myocardial stunning in isolated rat hearts. Male Sprague-Dawley rats (350-400 g) were randomized into three groups: control animals (n = 13) received no drugs; hearts from reperfused animals (n = 11) received 5 microM U74389G in the reperfusion solution; pretreated animals (n = 11) received 6 mg/kg U74389G by i.v. infusion 30 min before killing. Isolated, isovolumic rat hearts were subjected to 20 min of ischemia at 37 degrees C and subsequent reperfusion for 30 min. Left ventricular isovolumic developed pressure (LVDP), its first derivative (LVDPdP/dt), end-diastolic pressure (LVEDP), and the time constant of diastolic relaxation (tau) were measured. At baseline, no statistically significant differences were detected in systolic or diastolic function in hearts of rats with or without U74389G treatment. After reperfusion, LVDP stabilized at 87 and 92% in both drug-treated groups compared with 52% in the control group (p < 0.01) and dP/dtmax recovered to 101 and 110% of baseline compared with 58% in the control group (p < 0.01). Diastolic dysfunction showed significant improvement in both U74389G pretreatment groups. The increases in LVEDP and tau were 2.0- and 1.2-fold in pretreated hearts and 2,8-fold and 1.5-fold in drug-reperfused hearts, respectively (compared with 6-fold increases in LVEDP and a 2.5-fold increase in tau in controls; p < 0.05). In conclusion, whether administered before ischemia or during reperfusion, U74389G effectively attenuated the systolic and diastolic dysfunction in this model of myocardial stunning, probably protecting cell membranes from peroxidation by oxygen-derived metabolites.

Animals↗
PubMed1995

Coronary angioplasty in unstable angina: contemporary experience.

OBJECTIVE: To evaluate the role of percutaneous transluminal coronary angioplasty (PTCA) in the treatment of patients with unstable angina. DESIGN: Retrospective analysis of administrative records of all acute care hospital discharges at Robert Wood Johnson University Hospital from 1987 to 1993 with International Classification of Diseases, 9th revision, codes for coronary angioplasty and corresponding catheterization laboratory reports. SETTING: Tertiary care teaching hospital. RESULTS: Of 4826 PTCA cases, unstable angina was identified in 780 as the main indication for the procedure. Baseline clinical features of patients with unstable angina were not different from those in patients with stable angina. The overall success rate for PTCA in patients with unstable angina was significantly higher (707 of 780, 91%) than the success rate in patients with stable angina (3466 of 4046, 86%). The major complication rate in unstable angina patients was low (29 of 780, 3.7%) and did not differ from that in stable angina patients (136 of 4046, 3.4%). The success and complication rates in patients with unstable angina were analyzed in terms of time of PTCA, ie, early (less than 48 h from admission) versus late (48 h or more from admission). The procedure was successful in 343 of 380 (90%) patients treated early and 364 of 400 (91%) patients treated late (not significant), and the complication rates were low (12 of 380, 3.2% versus 17 of 400, 4.3%; not significant in both groups). However, length of hospital stay was considerably shorter for patients treated early than for patients treated late (4.5 +/- 3.3 days versus 10.4 +/- 6.6 days, respectively, P < 0.0001). CONCLUSION: Contemporary results of PTCA in patients with unstable angina parallel those reported for stable angina. Thus, PTCA appears to be an effective and safe treatment for unstable angina patients, and treating these patients soon after admission does not appear to affect the success or complication rates.

Angina, Unstable↗
PubMed1994

Chronic administration of nicardipine attenuates myocardial stunning in isolated rabbit hearts.

The purpose of this study was to evaluate the effects of the chronic administration of a calcium channel blocker, nicardipine, on systolic and diastolic alterations occurring during myocardial stunning in isolated rabbit hearts. Rabbits were pretreated with nicardipine 20 mg (O.I.D.) for 30 days. Then hearts were isolated (group II) and compared with control hearts (group I) in their response to 20 min of global ischemia and 30 min of reperfusion. Coronary flow and heart rate were kept constant. Left ventricular isovolumic developed pressure (LVDP), its first derivative (dP/dt), and end diastolic pressure (LVEDP) were measured. After isolation, no statistically significant changes were detected in LVDP, +dP/dtmax, LVEDP, or coronary resistance in hearts of rabbits with or without the pharmacological intervention. Early after the onset of reperfusion, LVDP and +dP/dtmax partially recovered in a similar way in groups I and II. Late in reperfusion LVDP stabilized at 48 +/- 7% in group I and 71 +/- 6% in group II (P < 0.05) and +dP/dtmax stabilized at 56 +/- 7% and 79 +/- 6% (P < 0.05), respectively. Diastolic dysfunction was manifested by a 217 +/- 39% increase in LVEDP (P < 0.05) in group I, and 140 +/- 31% in group II (P < 0.05). The isovolumic relaxation time constant (tau, tau) increased from 70 +/- 5 to 151 +/- 27 ms (P < 0.05), and from 66 +/- 6 to 97 +/- 10 ms. (NS) in groups I and II, respectively at 5 min of reperfusion. This relaxation parameter returned to normal values in the late reperfusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Resolution of coronary ischemic syndrome due to dislodgement of intraluminal thrombus during diagnostic cardiac catheterization.

Dislodgement of an intraluminal coronary thrombus occurred in a patient with unstable angina during diagnostic cardiac catheterization. The thrombus propagated into the systemic circulation without clinical manifestation of embolism. The procedure rendered the patient asymptomatic. The case illustrates the role of intraluminal coronary thrombus in unstable angina.

Angina, Unstable↗
PubMed1992

Arterial blood nicotine concentration and coronary vasoconstrictive effect of low-nicotine cigarette smoking.

Low-nicotine cigarettes have been advertised to the public as less harmful to the cardiovascular system. We studied the effects of smoking two low-nicotine cigarettes on arterial and venous blood nicotine levels, hemodynamics, and coronary vascular tone in 12 patients referred for diagnostic coronary arteriography. All were chronic smokers as evidenced by their elevated baseline arterial and venous cotinine blood levels (139 +/- 30 ng/ml and 155 +/- 34 ng/ml, respectively). High-resolution coronary angiograms were evaluated "blindly" before and after smoking. An electronic caliper was used to measure the diameter of disease-free coronary segments of the left anterior descending and circumflex arteries. Arterial nicotine levels rose from 5 +/- 1 ng/ml at baseline to 37 +/- 7 ng/ml (p less than 0.01) after the first cigarette was smoked and to 45 +/- 8 ng/ml (p less than 0.01) after the second cigarette. Venous nicotine levels rose from 8 +/- 2 ng at baseline to 15 +/- 3 ng/ml (p less than 0.05) after the first cigarette and to 20 +/- 3 ng/ml (p less than 0.01) after the second cigarette. After the first cigarette heart rate increased 8 +/- 2 beats/min (p less than 0.003) and double product 1229 +/- 400 beats/min x mm Hg (p less than 0.02). Compared to baseline values, after the second cigarette heart rate increased 9 +/- 1 beats/min (p less than 0.001) and double product 1767 +/- 486 beats/min x mm Hg (p less than 0.01). Systolic, diastolic, and mean blood pressure did not change significantly after either the first or second cigarette.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Catheterization↗
PubMed1992

Differential exercise effects of captopril and nadolol in patients with essential hypertension.

In a crossover study, 12 patients with mild to moderate hypertension were given placebo, captopril (12.5 to 50 mg three times a day), and nadolol (20 to 160 mg once a day) to control the resting diastolic blood pressure to a nearly identical degree (p less than 0.0001) (106.1 +/- 4 placebo, 89.6 +/- 8 captopril, 89.8 +/- 7 nadolol). Both drugs lowered (p less than 0.0004) systolic and diastolic blood pressure at rest and during exercise. However, systolic blood pressure lowering during exercise was more pronounced (p less than 0.05) with nadolol than with captopril (difference of 6 mmHg, 16 mmHg, and 21 mmHg at 5.0, 7.0, and 9.0 metabolic equivalents (METS) respectively). Heart rate was lower (p less than 0.05) at rest and during exercise with nadolol as compared with placebo and with captopril. These data imply different mechanisms of action of the two drugs at rest and during exercise and may help in selection of drug therapy in special patient subsets.

Adult↗