Assessment of right ventricular contractile performance after pulmonary resection.
Right ventricular (RV) performance deteriorates after pulmonary resection. The mechanism remains unclear and could be related to changes in loading conditions or contractility. To assess the role of alteration in RV contractility, we developed a simple and reliable means to measure RV contractile performance in adult patients. Using thermodilution methods and rapid volume infusion in the preoperative setting, the relationship between RV stroke work (RVSWI) and end-diastolic volume (RVEDVI), termed the preload recruitable stroke work relation, was plotted using linear regression. Experimental studies have demonstrated that the preload recruitable stroke work relation is a linear and load-insensitive index of RV contractile performance. Our study confirms this finding in adult patients: RVSWI = 0.33 (RVEDVI) - 20.4 (n = 108; r = 0.94; p < 0.01). Examination of RV pump function and hemodynamic parameters in the early postresection period (up to 24 hours postoperatively) revealed significant changes in loading conditions, but isochronal RVEDVI and RVSWI values were within the confidence limits of the preload recruitable stroke work relation. Thus, depressed RV contractility does not appear to play a predominant role in this early postoperative period. Further study in a larger patient population will be required to verify this observation and to assess RV performance beyond 24 hours after resection.
Division of Cardiothoracic Surgery, Medical University of South Carolina, Charleston 29425.
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Reed
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Dorman
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Spinale
D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000502:physiology*; D011013:Pneumonectomy / Q000009:adverse effects*; D012044:Regression Analysis; D013318:Stroke Volume / Q000502:physiology; D013815:Thermodilution; D016278:Ventricular Function, Right / Q000502:physiology*