Hemanath, T R (2014) Usefulness of Pulmonary Regurgitation Doppler Tracings in Predicting Outcome in Patients with Acute Inferior Wall Myocardial Infarction. Masters thesis, Madras Medical College, Chennai.
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Abstract
1 INTRODUCTION : Right ventricular (RV) acute myocardial infarction (AMI) occurs almost exclusively in setting of inferior wall left ventricular AMI. It is known that impaired left ventricular (LV) function is a major determinant of prognosis in patients surviving acute myocardial infarction (MI). However, little and controversial information is available on the relationship between right ventricular (RV) dysfunction and mortality. In a recent report focusing on the relationship between RV ejection fraction and long-term prognosis in patients with MI, Pfisterer and associates concluded that RV dysfunction contributes to the occurrence of cardiac death after MI independent of and in addition to LV impairment. Non invasive hemodynamic diagnostic criteria, available at the bedside, may be useful in the acute phase of MI to allow recognition of high-risk patients with RV involvement. Zehender [et al.] reported that ST-segment elevation in lead V4R at the time of admission was a strong predictor of in-hospital complications. However, the diagnostic accuracy of non invasive diagnostic criteria varies in different studies. RV echocardiographic study may represent a valuable alternative. Evaluation of RV systolic function as well as wall motion abnormalities or global RV function index is difficult because of inadequate apical windows and the unusual geometry of the right side of the heart. Continuous-wave Doppler tracings of physiologic pulmonary regurgitation (PR) are highly promising tools because PR flow is directly related to the pressure gradient between the pulmonary artery and the right ventricle by the Bernoulli equation Pulmonary regurgitation (PR) flow-derived Doppler curve was useful in recognizing RV involvement during the first 24 hours of AMI. A PR Doppler pattern depends mainly on the diastolic RV pressure pattern, which is altered during RV ischemia and characterized by a disproportionate increase of RV end diastolic pressure. This physical relation led us to hypothesize that a modification of RV pressure could modify the regurgitant flow pattern. To test this hypothesis, the present study was designed to systematically search for the presence of a pulmonary regurgitant jet in patients with inferior wall acute myocardial infarction and to compare the modifications of the flow pattern with clinical outcome. AIMS OF THE STUDY : 1. To evaluate the Doppler predictors of physiological pulmonary regurgitation in patients with right ventricular myocardial infarction in the setting of acute inferior wall acute myocardial infarction. 2. To assess the prognostic implications of Doppler characteristics of physiological pulmonary regurgitation with PR PHT _ 150 milliseconds and ratio between minimum and maximum Vmin / Vmax < 0.5 with respect to in-hospital events in patients with acute inferior wall myocardial infarction. CONCLUSIONS : 1. In patients with inferior wall acute myocardial infarction, flow Doppler tracings of pulmonary regurgitation are useful in the prediction of in hospital complications. PR derived parameters (PHT of PR _ 150 ms and V min /V max _ 0.5) were the excellent predictors of overall in-hospital complications. 2. PHT _ 150 ms and the minimal velocity of PR tracings in mid-diastole to the peak early diastolic velocity of PR ratio (V min /V max ) _ 0.5 were excellent predictors of RV involvement in the setting of inferior wall myocardial infarction. 3. Low output syndrome is a frequent, specific, and potentially severe complication of RV infarction.
| Item Type: | Thesis (Masters) |
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| Uncontrolled Keywords: | Pulmonary Regurgitation ; Doppler Tracings ; Predicting Outcome ; Patients ; Acute Inferior Wall ; Myocardial Infarction. |
| Subjects: | MEDICAL > Cardiology |
| Depositing User: | Kambaraman B |
| Date Deposited: | 05 Jul 2017 23:33 |
| Last Modified: | 05 Jul 2017 23:33 |
| URI: | http://repository-tnmgrmu.ac.in/id/eprint/1046 |
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