Myocardial color scan with 43K in ischemic heart disease

The value of myocardial scanning with 43K was assessed in 64 consecutive patients undergoing coronary arteriography, and in five young volunteers. Myocardial scans at rest detected only 16 of the 35 transmural infarcts documented on electrocardiograms, 11 of 11 anterior infarcts and five of 24 in other sites. Myocardial scans were obtained immediately after a graded exercise test in the five normal volunteers, in nine patients with normal coronary arteriograms and in 25 patients with atherosclerotic narrowing greater than 75% involving the left anterior descending artery, with or without disease of other coronary vessels. All patients with normal coronary arteriograms had normal myocardial scans. A regional perfusion deficit was observed after exercise in all six patients with single vessel disease, but in only 11 of the 19 patients with disease involving two or three vessels. Although the technique was specific, it lacked sensitivity, due mostly to poor resolution and the location of the disease.     

Perioperative cardiac arrhythmias in digitalized patients with ischemic heart disease (author's transl)

The purpose of this study was to establish the incidence of pre-operative digitalization by intravenous digoxin on cardiac arrhythmias in 24 patients with ischemic heart disease who underwent abdominal surgery. Ambulatory electrocardiographic monitoring was performed for 12 hours before digitalization, for 12 hours during digitalization (before surgery), for the whole period of anesthesia. General anesthesia used thiopentone, phenoperidine, pancuronium and suxamethonium for endotracheal intubation. No more premature ventricular (PVC) and auricular contractions were detected after digitalization and during anesthesia and surgery. But PVC with begeminism or severe bradycardia were recorded in two patients and episodes of "torsades de pointes" occurred in two other patients during endotracheal intubation. "Torsades de pointes" have never been reported after suxamethonium and endotracheal intubation in digitalized patients. Digitalization, ischemic heart disease, cardiac effects of suxamethonium might be factors of the onset of these first reported "torsades de pointes". In conclusion, after a pre-operative digitalization in the coronary patients the frequency of arrhythmias is not exaggerated during the pre- or per-operative period except during induction and intubation. As the role of suxamethonium seems to be important as a trigger for severe arrhythmias endotracheal intubation in digitalized coronary patients should be performed without suxamethonium.     

Regression of cardiac hypertrophy by 1,4 dihydropyridines in hypertensive patients

BACKGROUND: Left ventricular hypertrophy (LVH) represents an important intermediate end-point for, for example, the progression to heart failure. The persistence or progression of LVH despite antihypertensive therapy probably reflects the persistence or activation of mechanisms that negatively affect the cardiovascular system and, consequently, long-term outcome. EFFECT OF MODERN ANTIHYPERTENSIVE AGENTS: Long-term treatment with rapid-onset (and usually short-acting) dihydropyridine calcium antagonists is significantly less effective than angiotensin converting enzyme (ACE) inhibition in reducing left ventricular mass (LVM) in hypertensive patients. Both intermittent, and probably only partial, blood pressure control and an increase in sympathetic activity resulting from rapid decreases in blood pressure following dosing with such calcium antagonists may contribute to this relative ineffectiveness. In contrast, more recent studies have demonstrated that the longer acting dihydropyridines can reduce LVM as effectively as ACE inhibitors. DISTINCTIONS AMONG DIHYDROPYRIDINE CALCIUM ANTAGONISTS: Among the 1,4-dihydropyridines, drugs such as amlodipine and nifedipine in the gastrointestinal therapeutic system (GITS) maintain good blood pressure control over the full 24-h dosing period and do not cause dose-related increases in sympathetic activity. In contrast, extended-release felodipine has been shown to provide only intermittent blood pressure control, still leading to sympathetic activation. Notably, during short periods of noncompliance, blood pressure control is maintained with intrinsically long-acting agents such as amlodipine but not with slow-release formulations of short-acting agents such as nifedipine GITS. CONCLUSIONS: It is possible that the rate of onset and duration of action of various dihydropyridines may be pivotal factors in determining their effects on cardiovascular outcomes. Thus, the least beneficial dihydropyridines may be rapid-onset, short-acting agents, such as nifedipine capsules, and the most beneficial may be the slow-onset, long-acting agents such as amlodipine.     

Elevated platelet factor 4 and beta-thromboglobulin plasma levels in depressed patients with ischemic heart disease

Clinical depression has recently been recognized as an independent risk factor for cardiac mortality in patients after myocardial infarction. The underlying mechanisms of this increased mortality remain unclear. This study investigated the hypothesis that patients suffering from ischemic heart disease (IHD) and depression concurrently may have abnormal platelet activation resulting in an increased risk of thrombosis. Platelet factor 4 (PF4) and beta-thromboglobulin (beta-TG) were measured in young healthy control subjects, in nondepressed patients with IHD, and in depressed patients with IHD. Mean PF4 and beta-TG plasma levels in the IHD group with depression were found to be significantly higher than those of the control and IHD groups. This increase was not related to age, gender, racial difference, aspirin use, or severity of cardiac disease. This finding suggests that in depressed patients with IHD there is greater platelet activation, and may indicate an increased risk of thrombotic complications.     

Sotahexal pharmacodynamics in patients with ischemic heart disease

Therapeutic and prophylactic antiarrhythmic efficacy of sotalol hydrochloride (Sotahexal, "Hexal", Germany) and its effects in intracardiac hemodynamics and ECG parameters were evaluated in 95 patients with ischemic heart disease (IHD). The highest response to the drug was observed in ventricular extrasystoles, arterial flutter and fibrillation. Acute episodes of arrhythmia are managed by bolus administration of Sotahexal [correction of Hexal]. In this case greater risk of side effects exists. It is desirable to decide on the drug dose, mode of administration on the individual basis with due consideration of the risks and dangers which could be avoided in case of adequate instrumental control.     

Cardiopulmonary diagnosis in patients with ischemic heart disease

It may be established that the complex cardiopulmonary functional diagnostics in patients with chronic ischaemic heart disease obtained the following essential results: 1. The ergometrically achieved total functional capacity is clearly decreased in all age groups compared with the healthy persons, the differences are highly significant. 2. The proof of a coronary insufficiency got by the electrocardiogram after work is to be regarded as a factor limiting the functional capacity. 3. 72% of the patients reveal under load a PAEDP increased more than the normal of 25 Torr. After exclusion of a respiratory insufficiency these findings must be regarded as a disturbed myocardial function. 4. Thus the increased PAEDP under load apart from the well-known triad (angina pectoris under load, decreased total functional capacity, pathological ECG after work) is a sensitive and decisive factor for proving the disturbed cardial function in chronic ischaemic heart disease.     

Undetected cardiogenic shock in patients with congestive heart failure presenting to the emergency department

The purpose of this study was to examine the use of lactic acid levels and continuous central venous oxygen saturation (central venous oximetry) to stratify and treat patients with acutely decompensated end-stage chronic congestive heart failure (CHF) presenting to the emergency department. This prospective, convenience, non-outcome study was performed at an urban tertiary care hospital. Patients with end-stage CHF with an ejection fraction <30% presenting in decompensated CHF were eligible for the study. Patients were assessed using the Killip classification and New York Heart Association criteria. After lactic acid levels were obtained, patients were managed according to a standardized protocol guided by central venous oximetry. The patients were divided into high lactic acid (n = 22), low lactic acid (n = 5), and control groups (stable patients presenting to a cardiology clinic, n = 17) for comparison. There was no statistical difference in vital signs, or Killip and New York Heart Association criteria among the 3 groups. Central venous oxygen saturation was significantly lower in the high lactic acid group (32 +/- 12%) than in the normal lactic acid (51 +/- 13%) and control groups (60 +/- 6%) (p < 0.001). After treatment there was a significant decrease in lactic acid (-3.65 +/- 3.65 mM/L) and an increase in central venous oxygen saturation (32 +/- 13%) in the high lactic acid group compared with the normal lactic acid group (p < 0.001). A significant subset of patients with decompensated end-stage CHF present to the emergency department in occult shock and are clinically indistinguishable from patients with mildly decompensated CHF and stable CHF. Once identified, these patients require aggressive alternative management and disposition. Further study is necessary to identify whether this intervention impacts morbidity, mortality, and health care resource consumption.     

Myocardial protection for reoperative cardiac surgery in acquired heart disease

This study was designed to address three objectives in an experimental model of acute congestive heart failure (CHF) in the dog produced by rapid ventricular pacing. The first objective was to characterize cardiorenal and humoral responses before and during 2 h of acute CHF. The second objective was to determine the modulating action of iv furosemide upon these biologic responses to acute CHF, testing the hypothesis that furosemide-mediated natriuresis is associated with activation of the renin-angiotensin-aldosterone system (RAAS) compared with the control group. The third objective was to determine the modulating action of continuous low-dose atrial natriuretic factor (ANF) administration during acute CHF upon these biologic responses, testing the hypothesis that exogenous low-dose ANF would prevent activation of the RAAS and enhance the natriuretic action of furosemide. In the control group (Group 1; N = 6), plasma ANF increased after the onset of CHF; GFR and sodium excretion were maintained without activation of this RAAS despite arterial hypotension. In Group 2 (N = 6), furosemide in acute CHF increased sodium excretion but in association with a decrease in GFR and activation of the RAAS. Low-dose exogenous ANF and furosemide (Group 3; N = 6) in acute CHF were associated with a maintenance of GFR, no activation of the RAAS, and potentiation of furosemide-induced natriuresis. In summary, these studies demonstrate that furosemide potently increases sodium excretion in acute CHF, but with a decrease in GFR and activation of the RAAS. Low-dose ANF in acute CHF with furosemide maintains GFR, attenuates activation of the RAAS, and potentiates natriuresis.     

Direct evidence of impaired cardiac sympathetic innervation in essential hypertensive patients with left ventricular hypertrophy

Increased sympathetic nervous activity has been proposed as one of the causes of left ventricular hypertrophy (LVH) associated with hypertension. However, the precise relationship is not fully understood. METHODS: To elucidate the relationship between myocardial sympathetic nervous activity and LVH in patients with essential hypertension EHT), we performed 123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy in 49 patients with EHT and 17 normotensive control subjects. Sympathetic innervation of the left ventricle was evaluated using SPECT, and the whole heart uptake of the tracer was quantitatively assessed as the heart-to-mediastinum uptake ratio on both the early (15-min) and delayed (5-hr) images. Myocardial washout rate (MWR) of the tracer from 15 min to 5 hr after the isotope administration was also calculated. The left ventricular mass index (LVMI) was determined echocardiographically. RESULTS: In 49 hypertensive patients, there was a negative correlation between LVMI and heart-to-mediastinum uptake ratio on both the early and delayed images (r=-0.55, p < 0.0001; r=-0.63, p < 0.0001, respectively). In addition, there was a positive correlation between the LVMI and MWR of 123I-MIBG in these hypertensive patients (r=0.59, p < 0.0001). As for the regional uptake of the tracer, there was no significant difference between control subjects and hypertensive patients without cardiac hypertrophy, but a significant decrease of the uptake in the inferior and lateral regions was observed in hypertensive patients with cardiac hypertrophy. CONCLUSION: Patients with EHT had decreased accumulation and increased MWR of 123I-MIBG in proportion to the degree of LVH. Hypertensive patients with cardiac hypertrophy had impaired sympathetic innervation in the inferior and lateral regions of the left ventricle.     

Some metabolic relationships in young patients with ischemic heart disease

The interrelationships between body weight, insulin secretion and serum lipids were studied in 40 young white patients (mean age 37 years) with established ischemic heart disease (IHD), living in Johannesburg. None was severely obese, hypertensive or overtly diabetic. In general, strong positive correlations were found between body weight and insulin concentrations and between insulin levels and fasting serum triglycerides. However, insulin levels were relatively low in 4 patients with marked hypertriglyceridemia (above 350 mg/dl). These data are consistent with the postulate that insulin promotes (hepatic) triglyceride synthesis, but when there is gross hypertriglyceridemia peripheral triglyceride clearance becomes defective. Insignificant correlations were observed between body weight and serum lipids and between cholesterol and other metabolic variables. We conclude that there is a sequential link between increasing body weight, insulin secretion and triglyceride levels in young patients with IHD, but that cholesterolemia is independent of this axis.     

Alteration of plasma antithrombin III levels in ischemic heart disease

The amount of antithrombin III in plasma was determined quantitatively in 218 males between 45-60 years of age. The mean antithrombin III value was found to be low in the group with low risk for ischemic heart disease, intermediate in the group with high risk for ischemic heart disease and highest in the group with acute myocardial infarction. Concomitant study of kaolin-activated partial thromboplastin time revealed a sharp decrease in its mean value in the group with acute myocardial infarction. The high correlation between antithrombin III and kaolin-activated partial thromboplastin time for the entire population suggests that the development of ischemic heart disease is a gradual process and that failure of the damping mechanism results as an acute event. These findings may be useful in the determination of the coagulation state of these patients.     

Carotid body hypertrophy in patients with cystic fibrosis and cyanotic congenital heart disease

Austrobilharzia terrigalensis from Egretta sacra and Larus novaehollandiae at Heron Island, Great Barrier Reef, is described. The prosobranch snail Planaxis sulcatus is the natural intermediate host of A. terrigalensis at Heron Island. The life-cycle of A. terrigalensis was worked out using naturally and experimentally infected Planaxis sulcatus and experimentally infected chickens. Experiments to produce a dermatitis with cercariae of A. terrigalensis were negative. Austrobilharzia terrigalensis infects a wide range of natural hosts in Canada, continental United States, Hawaii and Australia, and uses different snail genera belonging to different families as intermediate hosts in different areas. The wide distribution is apparently due to the habits of some hosts which migrate between the northern and southern hemispheres.     

Aldosterone levels and cardiac hypertrophy in professional cyclists

Aldosterone has been associated with the development of cardiac hypertrophy and a correlation has been found between levels of aldosterone and the degree of cardiac hypertrophy in hypertensive patients. Our study aimed to test the relation between physiologic cardiac hypertrophy and serum aldosterone in a group of highly trained cyclists. Determination of the left ventricular mass index (LVMI) was performed in a group of 40 professional cyclists by using Devereux's formula with correction for body surface area. After an overnight fast, blood samples were collected and serum aldosterone levels were measured using RIA. LVMI and serum aldosterone were intercorrelated using linear regression analysis. Twenty-three of the 40 cyclists (58%) presented an LVMI > 130 g.m-1 and the other 17 subjects (42%) presented an LVMI < 130 g.m-1. Serum aldosterone levels did not correlate with LVMI in either of the groups (LVMI > 130 g.m-1, r = -0.089; LVMI < 130 g.m-1, r = 0.146). The lack of correlation of this hypertrophy with serum aldosterone levels suggests that physiologic hypertrophy of the athlete's heart could be caused by a different stimulus to that seen in pathologic hypertrophy of hypertensives.     

Aging and regression of cardiac hypertrophy in the hypertensive patient

OBJECTIVE: This study was aimed at determining factors acting on the regression of left ventricular hypertrophy due to essential hypertension. METHODS: It was a non-randomized, echocardiographic study of 60 previously untreated hypertensive subjects (20 to 75 years of age). RESULTS: Following a 5-year therapy, the decrease in the left ventricular mass was 14%. Normalization of blood pressure and reversal of left ventricular hypertrophy were obtained in 50% and 58% of patients, respectively. Patients of the non-responder group (non-response being defined as a less than 10% decrease in the left ventricular mass) were older and had a longer history of high blood pressure. A positive correlation was observed between age and decrease in the left ventricular mass, the latter being less marked in older patients. Antihypertensive drugs classes had no influence on reversal of left ventricular hypertrophy. CONCLUSION: Ageing may be a factor of resistance to the decrease in left ventricular mass with therapy. These results suggest that early screening and management of hypertension are essential.     

Frequency of silent ischemic heart disease in patients with diabetes mellitus

Early detection of silent ischaemia plays an important role in prevention of sudden cardiac death and acute myocardial infarction. More frequent occurrence of silent ischaemia in patients with diabetes mellitus and manifestations of ischaemic heart disease has been relayed in several studies. No studies aimed at frequency of occurrence of silent ischaemia in diabetic patients without clinical symptoms of ischaemic heart disease have been performed yet. Objectives of this study were the examination of the latter case. This study involved 67 patients with diabetes mellitus without clinical symptoms of ischaemic heart disease. The average duration time of diabetes mellitus was 11 years. The patients were divided in two groups. The first group included 26 patients with insulin dependent diabetes mellitus. The second group included 41 patients with non insulin dependent diabetes mellitus. The first control group consisted of 35 non diabetic patients with ischaemic heart disease, and the second control group consisted of 22 healthy volunteers. 24-hours ambulatory Holter monitoring and ECG exercise test were performed in all subjects. The diagnosis of silent ischaemia was established in patients with positive results of both examinations in ECG-records without any following pain. In case of only one positive results the dipyridamole stress echocardiography test with ECG was carried out to prove the diagnosis. It was proved, that silent ischaemia occurs in 19.2% of patients with insulin dependent diabetes mellitus and in 22% non insulin diabetic patients. No statistic differences between frequency of silent ischaemia occurrence in both groups were revealed. The application of 24-hours Holter monitoring combined with ECG-exercise stress test seems to be the best method in early recognition of silent ischaemia in diabetic patients.     

Relationship between insulin sensitivity and dehydroepiandrosterone sulfate in patients with ischemic heart disease

Schools are settings with high concentrations of young people with little exposure to Mycobacterium tuberculosis and greater risk of developing disease when infection occurs as the result of sporadic localized outbreaks. We studied two outbreaks in two elementary schools (A and B) after two cases of bacilliferous pulmonary tuberculosis were detected in teachers in 1990 and 1994. Contacts were trace din school A by the primary care physician and in school B by the pneumologist and public health authorities. Contacts were classified as belonging to the risk group (RG) or the low risk group (LRG). The RG was composed of 187 contacts in school A and 59 in school B. Individuals in the LRG numbered 429 and 116 respectively. Mantoux positives numbered 108 in the RG and 45 in the LRG in school A (p < 0.001). In school B 50 RG individuals and 29 LRG individuals were positive (p < 0.001). The proportion of Mantoux positives was greater in the RG of school B than in the RG of school A (p < 0.01), probably owing to longer time of evolution of disease and possible laryngeal involvement in the index case. Likewise, tuberculin positives were fewer in the LRG of school A than in the LRG of school B (p < 0.001), owing to the small size of the LRG in school A. Thirteen cases of tuberculosis were seen in school A, six of which called for drug prophylaxis after contacts were traced. The nature of the index case and the conditions of exposure are both important in such outbreaks, demonstrating the need to act appropriately to trace contacts, preferably under the supervision of a pneumologists.     

Effect of pulsatile and nonpulsatile assist on heart and kidney microcirculation with cardiogenic shock

To estimate microcirculation of the heart and kidney in pulsatile and nonpulsatile-assisted circulation, a comparison study was done using a swine model. Acute myocardial infarction was made by ligation of the left coronary artery branches. After cardiogenic shock, animals were divided into 3 groups as follows: Group C (n = 6), no assist provided; Group NP (n = 6), assisted by a nonpulsatile pump (Bio-Medicus BP-80); Group P (n = 6), supported by a pulsatile pump (Nippon Zeon). left coronary artery flow, endocardial and epicardial regional flows, and renal cortex and medulla tissue blood flows were measured. Left coronary artery flow and endocardial and epicardial tissue blood flows decreased in cardiogenic shock, and they recovered to the control level soon after support in both Group N and Group P. Renal medulla and cortex tissue blood flows decreased in cardiogenic shock, and these flows did not recover in either Group N or P. However, cortex blood flow in Group P did improve, but it did not improve in Group N. These results suggested that pulsatile assist was more effective than nonpulsatile assist for microcirculation after cardiogenic shock to avoid deterioration of major organ functions.