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Biomedical subjects

J Midwall

Publications and source records attributed to J Midwall.

9 recordsLinked to original sources
PubMed1990

CO2 power-assisted hand-held syringe: better visualization during diagnostic and interventional angiography.

Recent technology has produced high-flow and large-lumen catheters as well as other angiographic accessories to enhance the visualization of the coronary arteries during diagnostic and percutaneous transluminal coronary angioplasty (PTCA) procedures. In spite of these technological advances, there are still many cases in which the quality of the coronary angiography could be significantly improved. This paper reports on a clinical evaluation of a hand-held power syringe. The syringe offers the ability to power inject contrast safely and effectively during routine angiograms as well as through guiding catheters with the balloon catheter present during PTCA. At the same time, control of the injection is equal to that associated with manual syringes.

Angiography↗
PubMed1982

Coronary collateral function during exercise.

A totally occluded coronary vessel subtending a noninfarcted, entirely collateral-dependent myocardial region (NIECDMR) provides an opportunity to assess collateral perfusion during exercise stress. Collateral function was determined by analysis of exercise thallium-201 myocardial perfusion images from 31 patients who had at least one NIECDMR (total 41 NIECDMRs) documented during catheterization. Twenty-two of 41 NIECDMRs manifested exercise-induced perfusion defects and 19 were normally perfused. The exercise-negative NIECDMRs were further categorized: Group 1 NIECDMRs (n = 13) were associated with defects in other myocardial regions supplied by diseased vessels and were considered negative relative to other jeopardized regions; group 2 NIECDMRs (n = 6) were not associated with exercise-induced defects in other myocardial regions, which suggests that collateral perfusion was adequate during maximal exercise. Regions supplied by a diseased left anterior descending coronary artery manifested exercise defects regardless of collaterals, possibly because these regions were larger and required more perfusion. Angiographic indexes of collateral function did not clearly predict exercise results.

Adult↗
PubMed1982

Angina pectoris before and after myocardial infarction. Angiographic correlations.

Clinical, hemodynamic, and angiographic data were examined in 97 consecutive patients who underwent catheterization within two years of documented acute transmural myocardial infarction. The patients were divided according to the absence or presence of angina pectoris prior to myocardial infarction (groups 1 and 2). Group 1 had more females, was younger, and had a greater prevalence of one-vessel coronary artery disease. Of the patients surviving the myocardial infarction until hospital discharge, group 1 had fewer cases of postinfarction angina pectoris. The following were not statistically different for the two groups: mean time from infarction to catheterization, location of infarction, heart failure, coronary risk factors, mean left ventricular end-diastolic pressure, and mean ejection fraction. The angiographic significance of angina following infarction was analyzed in the 94 survivors. Patients with angina after infarction had a greater prevalence of two- and three-vessel coronary artery disease compared with patients without angina following infarction. Group 1 patients who had developed angina after infarction also had a greater prevalence of two- and three-vessel disease than patients who had no postinfarction angina. One-vessel disease was found in 82 percent of patients who had no angina before and after infarction. Infarction as the first manifestation of coronary artery disease (group 1) is often associated with one-vessel disease, especially if angina does not appear after infraction. Angina before or after infarction suggests two- and three-vessel disease.

Adult↗
PubMed1981

Preliminary experience with reversal of venoatrial flow in the diagnosis of tricuspid regurgitation.

Present methods of assessing tricuspid regurgitation are often unreliable. We present preliminary data concerning a new angiographic method for identification of tricuspid regurgitation which evaluates direction of flow of contrast media during right ventricular (RV) systole in the inferior vena cava (IVC) and hepatic veins following right atrial or IVC angiography. Group I consisted of 15 patients who had tricuspid regurgitation by conventional criteria. All 15 patients exhibited reversal of venoatrial flow by right atrial or inferior vena cava angiography. In a control group (group III) of 20 patients who do not have clinical tricuspid regurgitation, one patient demonstrated retrograde flow. Group II consisted of 11 patients with mitral valve disease and mild to moderate pulmonary hypertension. All 11 had no conventional evidence of tricuspid regurgitation; however, all 11 had the pathophysiologic potential for tricuspid regurgitation. Five of 11 had reversal of venoatrial flow during RV systole, suggesting the presence of clinically inapparent tricuspid. In conclusion, preliminary data suggest that angiographic reversal of venoatrial flow may be both sensitive and specific for the presence of tricuspid regurgitation. Further investigation with comparison to RV angiography and real-time echocardiography should be performed.

Adult↗
PubMed1980

Coronary artery spasm and perioperative cardiac arrest.

There has been increasing interest in coronary artery spasm as etiopathogenic mechanism for various syndromes associated with myocardial ischemia. A case with documented organic coronary artery disease is presented, in which coronary artery spasm was the probable cause of intraoperative and early postoperative cardiac arrest. We recommend that coronary spasm be considered in the differential diagnosis of perioperative cardiac arrest.

Angina Pectoris, Variant↗
PubMed1979

Eisenmenger's syndrome and pregnancy.

Two additional cases of successfully managed Eisenmenger's syndrome (ES) during pregnancy are described. A review of the literature on this subject revealed 115 reported cases, of which only 44 (including our two cases) were felt to be adequately documented, representing 70 pregnancies. These formed the material for statistical evaluation. Fifty-two per cent of all patients died in connection with pregnancy. Thirty and three-tenths per cent of all pregnancies results in maternal death. Maternal mortality in first, second, and third pregnancies was not significantly different. A high incidence of maternal death was assoicated with hypovolemia, thromboembolic phenomena and preeclampsia, but mortality was not higher in the toxemia than in the non-toxemia group. Cesarean sections and other operations are associated with extremely high maternal mortality during pregnancy. Thirty-four per cent of all vaginal deliveries, three out of four cesarean sections, and only 1 out of 14 pregnancy interruptions (the only one by hysterotomy) resulted in maternal death. Abortions are significantly safer than any kind of delivery (p less than 0.05). Ventricular septal defect (VSD) is the most frequent underlying shunt defect. Maternal mortality in association with VSD is higher (60%) than in association with atrial septal defect (ASD) (44%) and patent ductus arteriosus (PDA) (41.7%). The majority of maternal deaths occurred during or within the first week after delivery. Only 25.6 per cent of all pregnancies reached term. At least 54.9 per cent of all deliveries occurred prematurely. Thirty and two-tenths per cent of all infants showed intrauterine growth retardation. This represented almost half of all new borns with available information. Perinatal mortality reached 28.3 per cent and was significantly associated with prematurity (p less than 0.001). Pregnancy is contraindicated in patients with ES. Abortion is the treatment of choice, once pregnancy has occurred. Where interruption of pregnancy is refused, utmost care must be taken to assure maternal and fetal survival. A protocol for the management of such pregnancies is discussed on the basis of available information.

Abortion, Therapeutic↗
PubMed1978

Shunt flow and pulmonary hemodynamics during labor and delivery in the Eisenmenger syndrome.

The Eisenmenger syndrome carries a high mortality rate in a women during delivery and the immediate postpartum period. It has been suggested that marked changes in shunt flow and pulmonary hemodynamics may be responsible. These functions were studied under various physiologic and pharmacologic conditions during labor and delivery in a patient with the Eisenmenger syndrome. Uterine contractions were associated with a decrease in the ratio of pulmonary to systemic blood flow (Qp/Qs) from 1.58 to 1.05. The Qp/Qs ratio also decreased (to 0.83) when forceps were applied during uterine contractions. Epidural anesthesia, oxytocin and the supine position did not adversely affect pulmonary hemodynamics or shunt flow. On the basis of these results, if pregnancy cannot be terminated in a patient with the Eisenmenger syndrome, it is recommended that the patient be given high concentration of oxygen and epidural anesthesia and that serial arterial blood gas determinations be performed to detect changes in shunt flow.

Adult↗