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Evaluation of left ventricular early diastolic function after coronary artery bypass grafting relating to myocardial
1Department of Thoracic-Surgery, Saga Medical School, Japan.
Insights
Coronary artery bypass graft (CABG) surgery can lead to perioperative myocardial infarction (PMI). Early diastolic function impairment, detected by radionuclide ventriculography, is a sensitive indicator of cardiac damage following CABG.
Area of Science:
- Cardiology
- Cardiac Surgery
- Diagnostic Imaging
Background:
- Coronary artery bypass graft (CABG) surgery is a common procedure.
- Perioperative myocardial infarction (PMI) is a potential complication.
- Assessing cardiac function post-CABG is crucial for patient outcomes.
Purpose of the Study:
- To evaluate resting left ventricular early diastolic function.
- To determine the relationship between diastolic function and perioperative myocardial damage after CABG.
- To identify sensitive parameters for detecting cardiac dysfunction post-CABG.
Main Methods:
- Clinical study involving 48 patients undergoing CABG.
- Patients divided into two groups: uncomplicated (Group I) and complicated with PMI (Group II).
- Radionuclide ventriculography used to assess resting left ventricular early diastolic function.
Main Results:
- Group I (42 patients) showed no impairment in early diastolic parameters (peak filling rate, mean filling rate) post-CABG.
- Group II (6 patients) exhibited significantly decreased early diastolic parameters post-CABG and during follow-up.
- Time to peak filling rate normalized to diastolic time was prolonged in Group II, indicating impaired diastolic function.
Conclusions:
- Decreased early diastolic function and prolonged time to peak filling rate suggest perioperative myocardial infarction after CABG.
- Early diastolic function is a more sensitive indicator than systolic function for detecting cardiac impairment in patients with perioperative myocardial damage post-CABG.
Abstract:
This clinical study was undertaken to evaluate resting left ventricular early diastolic function relating to perioperative myocardial damage after coronary artery bypass graft (CABG) with radionuclide ventriculography. Forty-eight cases undergoing CABG were divided into two groups--Group I: not complicated with perioperative myocardial infarction (PMI), and Group II: complicated with PMI. In group I (42 cases), early diastolic parameters such as peak filling rate (1/3 PFR) and mean filling rate (1/3 FR(m)) during first third diastole were not impaired in the postoperative and follow up periods. In contrast, in Group II (6 cases), early diastolic parameters were significantly decreased to 157 +/- 74% EDV/sec of 1/3 PFR(pre op: 234 +/- 74, p less than 0.05) and 153 +/- 80% EVD/sec of 1/3 FR(m) (pre op: 231 +/- 86, p less than 0.05) in the postoperative period, and these parameters were still decreased in follow up period. The time to peak filling rate, normalized to diastolic time (TPFR/DT) of Group II cases, was severely prolonged in both periods. From these results, the complication of perioperative myocardial infarction was suggested by the decrease of early diastolic function and the prolongation of the time to peak filling rate. Early diastolic function was a more sensitive parameter than systolic function in the detection of impaired cardiac function in those cases with perioperative myocardial damage after CABG.