University of Twente Student Theses


Arterial blood pressure curve analysis in cardiogenic shock complicating myocardial infarction

Dülger, S. (2017) Arterial blood pressure curve analysis in cardiogenic shock complicating myocardial infarction.

Abstract:Introduction: Cardiogenic shock (CS) is the most common cause of death in patients with acute myo-cardial infarction. CS is defined by insufficient organ perfusion, caused by cardiac dysfunction. In-hos-pital mortality rates of CS patients are dramatically high, approximately 50 percent. CS is diagnosed based on the presence of hypotension, cardiac failure and some additional clinical findings suggest-ing decreased organ perfusion. The current definition of CS does not provide a grading that gives in-sight in the severity or “stage” of CS. Such a grading could guide medical therapies in the acute repre-sentation of CS, such as the timing of placement of mechanical assist devices. Since the arterial pres-sure pulse is determined by the pumping function of the heart and the bodies vasculature, the blood pressure curve might give additional insight in CS severity. The aim of this study is to gain insight in the value of the blood pressure curve morphology of predicting outcome in CS patients. Methods: An algorithm is developed to calculate various pressure, time slope, area, blood pressure variability and frequency related parameters. This thesis consists of three sub studies. In study I, the reliability and reproducibility of the parameters are investigated with blood pressure measurements during elective procedures in the catheterization lab. A subset of reliable parameters is chosen. In study II, these parameters are used to investigate blood pressure curve morphology differences in AMI patients that were treated with primary PCI and submitted to the ICU. In this retrospective co-hort study, differences were investigated between the ‘cardiac death’ group, ‘non-cardiac death’ group and ‘survival’ group. Factor analysis is performed to investigate correlation between parame-ters. In study III, the change of blood pressure curve parameters in time is investigated prospectively in STEMI patients treated with primary PCI. Results: Based on study I, only the parameters that are not related to anacrotic and dicrotic notch were regarded reliable, since the anacrotic -and dicrotic notch related parameters showed large vari-ation due to poor detection. With study II, thirteen parameters show a significant relation with either 30-day mortality or cardiac recovery in CS patients. These are: time to maximum slope, upstroke time, downstroke time, heart rate, left ventricular ejection time, systolic area under the curve, shock index, age adjusted shock index, stroke volume, cardiac output, cardiac power output, cardiac index and cardiac power index. Factor analysis revealed that all parameters are more or less correlated with each other, but can be reduced to three subgroups. These groups are: 1) shock index and area under the curves; 2) CO, CPO and SV; 3) Age adjusted shock index and heart rate. Heart rate, LVET and shock index were the strongest predictors of outcome and cardiac function. Though, these pa-rameters could not be combined in multivariate analysis, due to multi-colinearity. Only age, in combi-nation with one of these parameters, give a significant multivariate model with independent parame-ters. No significant changes in blood pressure curve morphology is seen over time in STEMI patients, except for a small decrease in diastolic pressure and MAP. Conclusion: ‘Shock index’, ‘LVET’, ‘HR’, ‘SV’, ‘CO’, ‘CPO’, ‘CI’, ‘time to maximum slope’, ‘upstroke time’ and ‘downstroke time’ are parameters that have potential to create a CS grading. Based on the cur-rent patient cohort, a complete CS grading cannot be developed yet.
Item Type:Essay (Master)
Faculty:TNW: Science and Technology
Subject:44 medicine
Programme:Technical Medicine MSc (60033)
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