Slow coronary run-off in patients with angina pectoris: clinical significance and thallium-201 scintigraphic study

To determine whether or not slow coronary flow (SF) depends on hemodynamic variables, we studied 17 patients (15 men, mean age = 47.8 years) with SF at coronariography. Exercise thallium-201 myocardial scintigraphy revealed perfusion abnormalities in 13 (76.4%) patients. We then selected 89 individuals submitted to cinecoronariography for comparison: 15 were normal and 74 had heart disease. The coronary flow velocity was evaluated by the number of heart beats (HB) needed for coronary artery dye filling. The patients in the SF group had normal hemodynamic variables which were significantly different from those of patients with heart disease (P = 0.001). Patients with heart disease needed no more than 4 HB to fill their arteries, in contrast to 6.88 +/- 1.68 (5 to 11) in the SF group (P < 0.0001). Thus, in our patients with myocardial scintigraphy suggesting ischemia, SF was found to be an event which did not depend on hemodynamic factors.

Holter monitoring in Chagas' heart disease

Electrocardiographic rhythm disturbance evaluation by Holter monitoring is increasingly becoming a useful methodologic tool for risk stratification as well as for therapeutic assessment in patients with Chagas' disease. Furthermore, late potential analyses, now being directly obtained from Holter recording has promising perspectives in enhancing identification of patients with high risk profiles for development of malignant ventricular arrhythmias. In addition, recently incorporated to Holter studies, heart rate variability analysis will certainly contribute to a better understanding of the characteristic autonomic nervous system disarray that commonly affects chagasic patients.

Signal-averaged electrocardiogram in chronic Chagas' heart disease

The aim of the study was to register the prevalence of late potentials (LP) in patients with chronic Chagas' heart disease (CCD) and the relationship with sustained ventricular tachycardia (SVT). 192 patients (96 males), mean age 42.9 years, with CCD were studied through a Signal Averaged ECG using time domain analysis. According to presence or absence of bundle branch block (BBB) and SVT, four groups of patients were created: Group I (n = 72): without SVT (VT-) and without BBB (BBB-): Group II (n = 27): with SVT (VT+) and BBB-; Group III (n = 63): VT- and with BBB (BBB+); and Group IV (N = 30): VT+ and BBB+. The LP was admitted, with 40 Hz filter, in the groups without BBB using standard criteria of the method. In the group with BBB, the root-mean-square amplitude of the last 40 ms (RMS) < = 14 microV was considered as an indicator of LP.

RESULTS

In groups I and II, LP was present in 21 (78%) of the patients with SVT and in 22 (31%) of the patients with SVT (p < 0.001), with Sensitivity (S) 78%; Specificity (SP) 70% and Accuracy (Ac) 72%. LP was present in 30 (48%) of the patients without and 20 (67%) of the patients with SVT, in groups III and IV. p = 0.066, with S = 66%; SP = 52%; and Ac = 57%. In the follow-up, there were 4 deaths unrelated to arrhythmic events, all of them did not have LP. Eight (29.6%) of the patients from group II and 4 (13%) from group IV presented recurrence of SVT and 91.6% of these patients had LP.

CONCLUSIONS

LP occurred in 77.7% of patients with SVT and without BBB. In the groups with BBB, there was association of LP with SVT in 66.6% of the cases. The recurrence of SVT was patient in 21% of the cases from which 91.6% had LP.

Plasma kinetics and biodistribution of a lipid emulsion resembling low-density lipoprotein in patients with acute leukemia

Low-density lipoprotein (LDL) could be used as a carrier of chemotherapeutic agents to neoplastic cells that overexpress LDL receptors (rLDL), but LDL is difficult to obtain and handle. Recently, it was observed that a protein-free emulsion resembling the lipid portion of LDL (LDE) behave like native LDL when injected into the bloodstream. In this study, the evidence that LDE is taken up by rLDL was expanded by comparing LDL and LDE plasma decay curves in rabbits and by competition experiments with lymphocytes. To verify whether LDE could be removed from the plasma by neoplastic cells with increased rLDL, LDE labeled with 14Ccholesteryl ester was injected into 14 patients with acute myeloid leukemia (AML) and into 7 with acute lymphocytic leukemia (ALL). In AML rLDL expression is increased but in ALL it is normal. LDE plasma fractional clearance rate (FCR, in h-1) was calculated from the remaining radioactivity measured in plasma samples collected during 24 h following injection. LDE FCR was 3-fold greater in AML than in ALL patients 0.192 +/- 0.210 (SD) and 0.066 +/- 0.033 h-1, respectively, P < 0.035. When LDE injection was repeated in 9 AML patients in hematological remission, LDE FCR diminished 66% compared to the pretreatment values (from 0.192 +/- 0.210 to 0.065 +/- 0.038 h-1, P < 0.02), so that it could be estimated that nearly 66% of the emulsion was taken up by AML cells and only 34% by the normal tissues. As expected, LDE FCR was unchanged in 4 patients with ALL in hematological remission (0.069 +/- 0.044 h-1). Gamma camera images obtained 6 h after the injection of 99mTc-label LDE into one patient with ALL showed biodistribution similar to that of LDL. In one AML patient LDE was comparatively more concentrated over the areas corresponding to the bone marrow infiltrated by AML cells. Our results indicate that LDE FCR is increased in a disease known to contain malignant cells that overexpress rLDL, suggesting that LDE is taken up by malignant cells with increased rLDL.

[Hospital bacteremia at the "Instituto do Coração do Hospital das Clínicas da FMUSP": a four-year retrospective study]

We conducted a retrospective study to establish mortality rates and prevalence of nosocomial bacteremias at our institute. We found 1.21 nosocomial bacteremias per 100 hospital discharges with an overall Mortality rate of 29.5%. Primary bacteremias increased during the four-year-study-period from 31 to 41%. Staphylococcus, both coagulase-positive and coagulase-negative, was the bacteria most frequently isolated. An abrupt increase in the isolation of P.aeruginosa occurred in 1992. We concluded that a blood-culture surveillance program is required for determining an endemic rate.

[Value of computerized exercise stress test in the differential diagnosis of ischemic phenomena of obstructive versus nonobstructive origin]

PURPOSE

To describe groups of patients who have obstructive and non-obstructive coronary artery disease, through computadorized exercise stress test.

METHODS

The test was done in 121 patients, all male, divided into 3 groups: GN group, 50 patients with normal electrocardiographic response to exercise; GLO group, 40 patients with obstructive coronary artery disease and GNO group, 31 patients with normal coronary arteries, showing one or more of the following entities: intramural coronary traject, coronary tortuosity, slow flow, mitral valve prolapse or left ventricular hypertrophy. GLO and GNO groups presented with abnormal response of the ST segment during exercise. The quantitative variables registered by computer were particularly analyzed as follows: STL (point Y depression), slope, index and ST segment integral. The magnitude of ST vector was visually measured and quantified. The statistic study was made through ANOVA and multiples comparison by the Scheffe's method, Fisher's test, quisquare and sensibility, specificity and accuracy calculation.

RESULTS

There was a significant statistic difference among the 3 groups relative to slope and index (p < 0.05). The integral variable of ST segment did not allow us to differentiate the GLO and GNO groups. In the association study between the ST vector magnitude and abnormal T loop, there was an increase in sensibility of 15% in the exercise stress test.

CONCLUSION

The ST segment slope below zero values, define patients having obstructive disease, and the opposite, non-obstructive disease. Values of ST segment index lower than -2 are linked to obstructive disease and higher than -2 linked to non-obstructive. Values of ST segment lower than -7 microV. s separate individuals with normal exercise stress test from those with ischemic type response. The magnitude of ST vector equal to or lower than 0.20mV define normal vectorcardiographic response to the exercise.

Lipoprotein(a) levels in systemic lupus erythematosus

OBJECTIVE

To determine lipoprotein(a) [Lp(a)] levels in systemic lupus erythematosus (SLE) and its possible correlation with thrombosis, disease activity, anticardiolipin antibodies (aCL) and steroid therapy.

METHODS

Serum Lp(a) levels were determined by radioimmunoassay (RIA) in 34 Caucasian patients with SLE and compared to 66 healthy subjects.

RESULTS

In patients with SLE Lp(a) levels were higher than in controls (42 +/- 35 vs 26 +/- 25 mg/dl, p = 0.01). Lp(a) levels were high (> or = 30 mg/dl) in 56% of the patients with SLE and in 30% of controls (p = 0.02) but were not correlated with the clinical and laboratory findings.

CONCLUSIONS

Lp(a) levels are significantly higher in patients with SLE and are not influenced by disease activity, thrombosis, aCL and steroid therapy.

[Myocardial revascularization surgery in an 87-year-old patient. A case report]

A 87 years old patient, with independent life style, presented unstable angina in spite of medication. Cineangiocoronariography demonstrated severe triarterial lesions, with good distal segments and preserved left ventricular contractility. Three saphenous vein grafts were performed. Some clinical measures were employed: a) manitol, furosemide and Ringer solution were infused two hours before and during surgery; the infusion was maintaned during the two postoperative days; b) limited use of nephrotoxic agents; c) adequate doses of medication; d) red cells infusion in spite of higher hematocrit levels than those present in younger patients; e) early start of respiratory physiotherapy and deambulation. Mean arterial pressure was maintained over 80 mm/Hg during surgery. During the period of extracorporeal circulation a hollow capillary membrane oxygenador was employed. Immediate postoperative course, up till six months, was free of coronary insufficiency symptoms. This case demonstrates the benefits of myocardial revascularization in elderly patients, respecting some peculiarities of the geriatric therapeutics.

Experimental myocardial infarction: effect of methylprednisolone on myocardial blood flow after reperfusion

The effect of methylprednisolone on the distribution of myocardial flow during ischemia and after reperfusion was determined in 10 treated and 11 control dogs. Methylprednisolone, 30 mg/kg, was administered iv after occlusion. Transmural blood flow and the endo/epicardial ratio in the normal and ischemic zones was measured by injecting 141Ce- and 85Sr-labelled microspheres after 90 min of ischemia and 30 min after reperfusion, respectively. During ischemia, transmural blood flow (ml g-1 min-1) in the ischemic zone was higher in treated animals than in controls (0.25 +/- 0.04 vs 0.15 +/- 0.03; P less than 0.05) but not different in the normal zone for both groups (1.36 +/- 0.14 vs 1.15 +/- 0.10; P greater than 0.05). The endo/epicardial ratio of the ischemic zone was low but similar for both groups during ischemia (0.43 +/- 0.07 vs 0.40 +/- 0.09; P greater than 0.05). After reperfusion, transmural blood flow increased significantly in treated (0.25 +/- 0.13 vs 1.36 +/- 0.13; P less than 0.0005) as well as in control animals (0.15 +/- 0.03 vs 1.63 +/- 0.14; P greater than 0.0005), reaching similar values (1.36 +/- 0.13 vs 1.63 +/- 0.14; P greater than 0.05). The endo/epicardial ratio also increased during reperfusion in both treated (0.43 +/- 0.07 vs 1.12 +/- 0.12; P less than 0.0005) and control animals (0.40 +/- 0.90 vs 1.03 +/- 0.19; P less than 0.025). These data show that although methylprednisolone-treated dogs had higher myocardial blood flow during ischemia, after reperfusion the increase in flow in the ischemic zone of treated and control dogs was of the same magnitude.