Case Analysis study of Post Myocardial Infarction Cardiac Failure

INTRODUCTION: Post infarction cardiac failure is one among the common complication of acute myocardial infarction. It is clinically observed when the contractile dysfunction of the heart, resulting from Acute myocardial infarction exceeds more than 25 to 40% of left ventricular diameter, barring the limitation observed as compensation mechanism by means of increased adrenergic activity and increased Left ventricular End-diastolic volume; when these compensatory mechanisms are overwhelmed, the increased LVEDV will result in increased myocardial wall tension and augment the myocardial oxygen demand, predisposing further augmentation of increased left ventricular end diastolic pressure and pulmonary venous congestion. For individuals free of Heart failure at age to 40 years, the remaining life time risk for developing heart failure is 21% for men and 20.3% for women. If mechanical complications are associated in Acute myocardial infarction such as Papillary muscle dysfunction, Mitral regurgitation, Ventricular septal rupture, further increase in left ventricular volume will result in further increase in wall tension and oxygen demand and pulmonary venous congestion and consequent left heart failure. Percentage to changes in norepinephrine and BNP over 12 months are independently associated with corresponding changes in morbidity and mortality. The symptoms of post - myocardial infarction cardaic failure are varied. It is recognized in the usual way by the advent of dysponea, fine basal rales, orthopnea, gallop rhythm, distended neck veins, hepatic engorgement, positive abdomino - jugular reflux and in more advanced cases peripheral edema. In severe cases they may present as expectoration of frothy sputum and central cyanosis. Rarely it is diagnosed with the help of X-ray chest with slight enlargement of cardiac stilhoutte and alveolar infiltrate of pulmonary edema, in the absence of clinical features. In general, male gender, the presence of coronary artery disease as the etiology of heart failure, the presence of an audible S3 or elevated JVP, low pulse and systolic arterial pressures, a high NYHA classes and reduced exercise capacity, have been shown to be associated with increased mortality. AIM OF THE STUDY: It is a prospective study of 100 cases of post - myocardial infarction - cardiac failure analyzing various factors like 1. Incidence: a. Age, b. Sex. 2. Influences: a. No. of infarction, b. Associated systemic illness, c. Dietary Habits, d. Occupational Stress, e. Body mass index, f. Substance abuse like smoking, alochol and drugs on clinical presentations, with reference to history, symptomatology, electrocardiogram and 2-Dimentional Echocardiogram and X-ray chest in selective cases. MATERIALS AND METHODS: This study was conducted at Madras Medical College, Chennai - 3, during the period of May 2004 to January 2006. Hundred cases of post myocardial infarction cardiac failure were included in this study. The patients were selected from those who were admitted in the medical wards and those who attend cardiology clinics. All the patients were evaluated in detail by clinical, ECG, X-ray, Echo - methods. In the analysis of clinical findings elaborate history regarding the modes of presentation and symptoms were sought for and recorded. Symptoms of cardiac failure such as NYHA, Grade dyspnoea, orthopnoea, PND, NYHA classifiaction of angina, palpitation, fatiguability, giddiness, syncopy, coughs, hemoptysis, dysphagia and hoarseness of voice are recorded. In history taking, number of previous infarction, time window between onset of chest pain and admission in hospital, angina and dyspnoea free interval between attacks were recorded, systemic diseases, treatment regularity, relevant family history, substance abuse, basic investigations and their findings were also documented. All volunteers of this study were subjected to ECG, echo study and X-ray (in selective cases). In echo studies, the territory of wall motion abnormalities, systolic, diastolic dysfunction, presence and absence of pericardial effusion, clot, aneurysm and calcification were noted. Left atrial and right ventricular dilatation were looked into for the presence of residual post MI failure especially when they are planned for discharge. A copy of the echo cardiogram was issued to the patient for the future reference and follow up. In relevant patients blood investigation were done to study the biochemical parameters. CONCLUSIONS: 1. Post MI cardiac failure is commoner in urban dwelling (54%) than rural (30%) than semi urban (16%). 2. Post infarction cardiac failure is common in male (90%). After 40 years of age raising incidence are observed in female. 3. Smoking (More than 20 cigarette's per day) and consumption of alcohol has linear relationship with incidence of post MI failure. 4. Sedentary Life Styles (58%), mixed diet pattern (78%), consumption of sheep or goat flesh rather chicken, egg, fish have positive and profound influence over the occurrence of post MI failure. 5. Most common clinical presentation is Tachycardia 100%, in a patient with chest pain or history of infarction. This is followed by cardiamegaly in 60% of case and LVS3 in 44% of patients and pansystolic murmur in 44%. 6. Most common symptomatology are NYHA IV 28%, orthopnoea 60% and Paroxysmal Nocturnal Dysponea 52%, NYHA III 32%, Rest angina 44%, effort angina 32%, nocturnal 30% and postural cough 26%. 7. Systemic high blood pressure with infarction (48%) was the single most aetiological factor for Post MI cardiac failure. Multitude of other factors, NIDDM 24%, history of one or two more infarction, chronic obstructive airway disease (16%) are other factors for post MI cardiac failure. 8. Anteroseptal wall and extensive anterior wall infarctions are the leading causes of post MI cardiac failure (24%) each. Perinfarction blocks (18%), ventricular premature contractions (10%) are the ECG manifestations concluded. 9. In 2D echo analysis hypokinesia (72%), Systolic Dysfunction (72%), small pericardial effusion (32%), Papillary muscle - Dysfunction / Mitral Regurgitation (PMD / MR) (22%), valves calcification (20%), left atrial enlargement (42%) are the observations made.