[Magnesium in cardiology]. / Magnezijum u kardiologiji.

INTRODUCTION: Magnesium is an oligo-element which has an important effect on the myocardial function and peripheral vascular system. MATERIAL AND METHODS: The experiences of other authors as well as other papers have been analyzed. RESULTS: Magnesium participates in over 300 enzymatic reactions in the human organism. It may be found in drinking water and food through which it is substituted. According to WHO, there is a good correlation between Ca++/Mg++ ratio in drinking water and frequency of cardiac events. Higher Mg++ quantity reduces coronary disease. Decreased Mg++ quantity in plasma has been registered in patients with acute myocardial infarction (AMI), coronary patients and patients with heart failure. Various rhythm disturbances, particularly Torsade de points are related to hypomagnesemia. Diuretics and some cytostatics, and antibiotics decrease Mg++ in plasma, erythrocytes and muscles. Decreased Mg++ have been found in alcoholics, diabetics and Crohn disease, which are in certain cases related to existing heart rhythm disturbances. In cardiology it is proved that Mg++ are beneficial in AMI, protection during open heart surgery and treatment and prevention of heart surgery and heart rhythm disturbances. The use of Mg++ in vasospastic angina pectoris, Raynaud's disease and cardiomyopathies due to cytostatics is still in the process of investigation. It is still a matter of discussion whether Mg++ should be administered in these conditions or only when its quantities are reduced. Do Mg++ values in plasma indicate its total presence in the organism? Where should Mg++ be administered as therapy, in which doses and how rapidly? Should preventive addition of Mg++ in drinking water reduce heart disease and prolong life? There are neither many answers nor real conclusions on Mg++ significance in cardiology. However, some encouraging results about its use indicate the significance of further investigations. DISCUSSION: It has been accepted by the authors all over the world that the role of magnesium is of great importance in prevention and treatment of cardiac patients. CONCLUSION: Our first experiences are in accordance with other studies.

[Arrhythmogenic right ventricular dysplasia]. / Aritmogena displazija desnog ventrikla.

INTRODUCTION: Arrhythmogenic right ventricular dysplasia (ARVD), disease of uncertain etiology, is characterized by fibrofatty collections in the right ventricular myocardium, premature ventricular complexes with left bundle branch block (LBBB) morphology, ventricular tachycardia and fibrillation. GOALS: To point out diagnostic methods for this progressive disease and to analyze differential diagnosis and significance of arrhythmogenic right ventricular dysplasia in young, active athletes. RESULTS: Arrhythmogenic right ventricular disease can be asymptomatic or manifested (syncope). It is not uncommon that the first evidence of the disease is ventricular tachycardia/fibrillation or sudden cardiac death. Results of electrocardiography, echocardiography, invasive and other methods can, even after few years, be negative for ARVD. The most significant ECG features are inverese T wave in precordial V1-V3 leads and widened QRS complex (> 120 ms) in V1 lead. Significant echocardiographic features and data obtained by invasive hemodynamic examinations are: dilated right ventricle, left and right ventricular end-diastolic diameter ratio less then 0.5, hypokinetic/akinetic areas involving the wall of the right ventricle, predominantly inferobasal, apical and wall of the left ventricular outflow tract. Findings may also include deep fissures among hypertrophied trabeculae. Biopsy may reveal fibrofatty tissue in hypo/akinetic regions of the right ventricular myocardium. DISCUSSION AND CONCLUSION: Since arrhythmogenic right ventricular dysplasia is diagnosed in predominantly young population, not uncommonly athletes, and since it may be cause of sudden cardiac death, there must be a high degree of suspicion in cases with activity related VT/VF and positive family history (it is proposed that it is a hereditary disease).

[Sudden cardiac death]. / Iznenadna srcana smrt.

Sudden death occurs unexpectedly, within 24 hours after the onset of subjective symptoms with or without known preexisting conditions. According to Framingham Heart Study, during a 20-year follow-up, 13% of deceased have died of sudden death. Most frequently it occurs in the first 6 months in infants and in the period 45-75 years of age. In more than 80% of cases sudden death is caused by coronary disease, while in 5% of cases the cause is cerebrovascular insult. The mechanism of sudden death is ventricular fibrillation in 65-85%, ventricular tachycardia in 7-10% and electromechanical dissociation in 20-30%. Sometimes sudden death may be caused iatrogenically, by drug intoxication, catheterization and reflex mechanisms--vasovagal reflex and sinus caroticus reflex. Pathoanatomical finding can be positive on myocardium like fibrosis, edema, individual necrosis, cell infiltration or it can be unchanged. In cases of heart failure, resuscitation is performed: airway maintenance, artificial respiration, artificial circulation, drug therapy and electrotherapy. Prevention of sudden death means detection of high-risk patients and application of medical treatment in order to postpone it. Coronary patients with sustained myocardial infarction and ejection fraction lower than 30% and registered tachycardia represent high-risk patients.

[Shock]. / Sok.

UNLABELLED: Shock is a consequence of disturbed circulation and decreased blood perfusion of tissues which, on the whole, cause functional and morphological impairments of organic systems. Occurrence of shock is not high, but it is significant due to bad prognosis and high mortality rate. CLASSIFICATION: This is one of the classifications of shock: cardiogenic, extracardiogenic-obstructive, oligentic and distributive shock. PATHOPHYSIOLOGIC MECHANISMS OF SHOCK: Regardless of the cause of shock, the clinical picture is dominated by hypotension mostly caused by decrease of minute volume (septic shock may be an exception--minute volume might be high). Due to hypotension a lot of compensatory mechanisms are activated and in the beginning showing the compensatory phase of disease and if nothing is done decompensatory and in the end irreversible phase of shock occurs with fatal outcome. The clinical picture depends on the etiology of shock, type of shock, but it also has certain specificities. PROGNOSIS: The prognosis depends on the clinical picture dominated by the following symptoms: hypotension, decreased diuresis, acidosis, consciousness disorders, tachypnea, peripheral cyanosis, cold and damp skin. MANAGEMENT: These patients are managed in intensive care units, where the following parameters are followed-up: arterial pressure, central venous pressure, minute heart volume, systemic vascular resistance, diuresis, continual follow-up of heart rate, breathing and consciousness. In treatment of shock it is necessary to: normalize the circulatory volume, establish electrolyte balance, regulate glycemia and acid-base status, compensate the volume, calm the patient and alleviate pain.

[Asymptomatic myocardial ischemia before and after surgical revascularization in patients with multivessel occlusive coronary disease]. / Asimptomatska ishemija miokarda pre i posle hirurske revaskularizacije kod bolesnika sa visesudovnom okluzivnom koronarnom bolescu.

INTRODUCTION: The objective of this study was to examine the occurrence of asymptomatic myocardial ischemia prior to and after myocardial revascularization in patients with multivessel occlusive coronary disease. Asymptomatic ischemia can be described as real ischemia without anginal pain or other ischemic symptoms in patients with coronary disease or coronary artery spasm. Our study examined silent ischemia after myocardial revascularization. Early detection of silent ischemia is important for prevention of cardiac incidents. MATERIAL AND METHODS: We have examined patients with multivessel coronary disease with occurrence of continued preoperative silent ischemia. All patients have undergone ECG examination, exercise stress test and Holter-monitoring prior to and after myocardial revascularization. RESULTS: The investigation comprised 27 patients and their average age was 54.5 years. All patients with silent ischemia had a multivessel occlusive coronary disease and have undergone myocardial revascularization managed with triple or quadruple aortocoronary bypass surgery. Exercise stress test was performed postoperatively in elder patients, as well as ECG and Holter-monitoring. Silent ischemia was established in 21.6% of patients, while in 87.5% untreated diabetes mellitus was diagnosed. Silent ischemia most often occurred in the early morning hours and it was frequently associated with heart rhythm disturbances (VES) whereas these rhythm disturbances depended on the length of the ischemic episode. Intermittent 2nd degree atrioventricular block was found in one patient. CONCLUSION: Silent myocardial ischemia occurred in 21% of patients after myocardial revascularization. It is most often detected in the early morning hours and is associated with ventricular rhythm disorders. Silent ischemia is easily detected by simple examination procedures providing adequate therapy and prevention of cardiac incidents.

Incidences and surgical aspects of cardiac myxomas in Bulgaria.

63 patients with cardiac tumors underwent operative treatment between January 1970 and December 1988. Three additional patients refused the operation, despite the large left atrial myxomas and obstruction of the mitral valve, recognized by echocardiography. 62 patients had benign tumors: the only malignant neoplasm was a fibrosarcoma, originating from the right ventricle. Myxomas were found in 57 patients: 54 were located in the left and 2 in the right atrium. In one case the myxoma originated from the left ventricle. The hospital mortality of the 22 patients who underwent excision of cardiac myxomas between 1970 and 1984 was 18.18% (4 deaths), and 2.44% (1 death) of 41 patients operated on from 1984 to 1988 for cardiac tumors (35 of them with myxomas). During the follow-up time of 6 to 140 months, recurrence of myxomas occurred in only one patient, 4 years after surgery for multifocal myxoma in the left atrium. Surgical excision of the myxoma is the only acceptable therapy able to cure. Without surgical treatment, the medium and long-term prognosis is fatal. Therefore once the cardiac myxoma is identified by two-dimensional echocardiography, the tumor should be removed even in patients without symptoms. The removal of myxomas doesn't require excision of the full thickness of the interatrial septum or ventricular wall. The risk of postoperative arrhythmias after extensive excision increases. Conduction disturbances may be related to the resection of a large area of the atrial septum or wall. No recurrences have been registered after less radical procedures-- removal with excision only of the underlying endocard.

[The potentials of pulse Doppler echocardiography for the diagnosis and determination of the degree of mitral stenosis]. / Vuzmozhnosti na pulsovata doplerova ekhokardiografiia za razpoznavane i opredeliane stepenta na mitralnata stenoza.

84 persons were examined: 61 patients with rheumatic mitral valve stenosis (21 men and 40 women), mean age 39.38 +/- 11.2 years and 23 healthy controls (14 men and 9 women), mean age 25.62 +/- 3.8 years. The morphologic and quantitative characteristics of the diastolic part of the pulse Doppler echocardiographic signal of mitral circulation analyzed by histogram of the time intervals show highly significant statistical differences between the patients with mitral valve stenosis and the healthy controls (100% specificity and sensitivity). The differentiation of mild and moderate from severe mitral stenosis by pulse Doppler echocardiography of mitral valve circulation, analyzed by histogram of the time intervals, is achieved with satisfactory precision by determination of the speed of the circulation fall in the early 1/3 of the diastole. The pulse Doppler echocardiograph performed by a transducer with 2.5 mHz frequency and the simultaneous M-echocardiography, the Doppler effect being analyzed by histogram of the time intervals, do not allow the precise determination of the degree of mitral valve stenosis.

[Dissecting aortic aneurysm]. / Disekirashta anevrizma na aortata.

Twenty cases with aortic dissecting aneurysm (ADA) are presented, at an average age of 52.5 (from 14 to 75), 15 of them males and 5--females. Nineteen had acute form of the disease and 1--chronic. Etiology, clinical picture, diagnostic approach and treatment were analyzed. Pain as leading symptom was present in all patients with various intensity and predominantly antero-thoracal localization. Seventeen of the patients (70%) were in shock at admittance. Pulse asymmetry was established in 8 (40%) and in 4, out of 12 cases (33%) with ADA, complicated by cardiac tamponade, a freshly appeared diastolic murmur was present. Enlarged aortic shadow at X-ray investigation had 14 (70%) of the patients with a dynamics of the enlargement in 5 patients. The disease has been clinically diagnosed in 19 (95) of the patients. Five out of 20 patients underwent operation, two of them followed for two years after the surgical treatment. Only one patient out of the non-operated 15 patients, survived. The modes of therapeutic behaviour are discussed on the base of the authors' experience and literature data.

[Work test in acquired heart valve defects]. / Rabotna proba pri pridobiti surdechni klapni porotsi.

The physical working capacity to 34 patients with acquired cardiac valvular defects and right catheterization was determined via bicycle ergometer "Zimermann" (GDR). Reverse correlation was established between the physical capacity and pressure 0,93 +/- 0,13 kPa (7,0 +/- 1,0 mm Hg) in right auricle (p less than 0,01), 0,9 +/- 0,27 kPa (6,75 +/- 2,12 mm Hg)--in right auricle (p less than 0,01), 4,18 +/- 1,21 kPa (31,5 +/- 9,02 mm Hg)--in pulmonary artery (p less than 0,05) and 2,66 +/- 0,26 kPa (9,19 +/- 6,76 mm Hg)--in pulmonary capillaries (p less than 0,5). The data from the study coincide with those of the other researchers who established reverse correlation between the physical working capacity and functional class according to New York Cardiological Association. The degree of mitral-valvular stenosisin "pure" or dominating mitral stenosis, degree and duration of cardiac insufficiency, duration of cardiac defect and auricular fibrillation.