Abstract: Acute myocardial infarction (AMI) is a common disease with serious consequences in mortality, morbidity, and cost to the society. Inferior myocardial infarctions (IMI) accounts for about30% to 50% of all acute myocardial infarctions[1]. Althoughan infarction involving the inferior wall might occuras an isolated event, it is more often associated withan posterior myocardial infarction. Dysrhythmias are a relatively common complication of inferior wall MIs. [2][3].
Aim:The purpose of our retrospective analysis was to identify features of the course IMI and incidence of complications (AV blockade, cardiogenic shock, tachycardia, arrhythmias etc)
Materials and methods: The data of 36 case histories of patients with inferior myocardial infarctions who were treated in the cardiology and cardiac reanimation departments of the TMA 3 clinic from January to October in 2017. Analyzed data of 12-lead ECG and ECG by Nebu.
Results: The average age of patients with Inferior myocardial infarctions (IMI) is63,7± 9,14 years (47-78 years). Of these, 15 women (41.6%) and 21 men (58.3%). A classic symptom of an inferior wall MI specifically, was nausea and vomiting diagnosed in 10 patients (27.7%), no chest pain in 8 patients. One of the significantly feature was that 22 patients with IMI (61.1%) had diabetes mellitus. Arterial hypertension in primary examination was determined in 16 (44.4%) of 36 patients, moderate arterial hypotension was noted in 10 (27.7%) of 36 patients. Pulmonary edema was diagnosed in 10 (27.7%) while collapse or cardiogenic shock occurred in 4 (11.1%) of 36 patients. Tachycardia with an increase in myocardial oxygen demand (heart rate more than 120 per minute) was first observed in 6 patients (16.7%) from 36 patients. Moderate tachycardia (heart rate 90-110 per minute) was established in 4 (11.1%), bradycardia - in 4 (11.1%) of 36, heart rate was not determined in 1 of 36 patients.
Incidence of conduction abnormalities was occurred in 5 patients, first degree AV block in 2 patients (5.5%), complete AV block with nodal rhythm- in 8,3% of cases (3 of 36). Total number of patients with paroxysmal atrial fibrillation was observed in 22.2% of cases (8 of 36), ventricular fibrillation- in 11.1% of cases (4 of 36). In-hospital death was accounted 8.3%(3 of 36).
Conclusion: Chest pain which the most common complaint in MI, can be the second degree complaint, while symptoms nausea and vomiting could be primary complaints, as result of the vagal nerve stimulation. Acute occlusion of the right coronary artery, resulting in an inferior and/or posterior infarct would therefore also result in AV nodal ischemia and various degrees of AV blocks.The presence of complete heart block and ventricular fibrillation independently predicted higher in-hospital mortality.
References:
- Randomized trial of intravenous streptokinase, oral aspirin, both, neither among 17,187 cases of suspected acute myocardial infarction: ISIS-2.ISIS-2 (Second International Study of Infarct Survival Collaborative Group. J Am Coll Cardiol 1988; 12: 3A-13A.
- Use of the Electrocardiogram in Acute Myocardial Infarction:Peter J. Zimetbaum, M.D., and Mark E. Josephson, M.D. N Engl J Med 2003; 348:933-940
- Right ventricular myocardial infarction: presentation and acute outcomes. Chockalingam A1, Gnanavelu G, Subramaniam T, Dorairajan S, Chockalingam V. 2005 Jul-Aug;56(4):371-6.