Investigation of heart rate variability of patients undergoing coronary artery bypass grafting (CABG).

BACKGROUND: Myocardial revascularization by coronary artery bypass grafting (CABG) is an effective measure for reducing symptoms and mortality in patients with unstable or severe coronary artery disease (CAD). Autonomic function can be estimated non-invasively using heart rate variability (HRV). HRV of patients undergoing CABG is investigated before and after CABG using a soft-decision wavelet based spectral analysis. OBJECTIVE: The main purpose of this work is to evaluate non-invasively HRV in patients undergoing CABG before operation; and to monitor the status of patients through HRV investigation on day 6 and day 30 after the CABG operation. The study intends to contribute scientific value to understanding the effect of CABG on the cardiovascular autonomic function and surgical outcome. METHODS: The soft-decision wavelet-based technique is used in this work in order to measure the power spectral density of the three main bands (VLF, LF, and HF) of HRV in 24 patients undergoing CABG operation, before the operation (Group 1: G1), and 6 days after operation (Group 2: G2) and 30 days after operation (Group 3: G3). The data is obtained from Sultan Qaboos University hospital in Oman. RESULTS: The HF power increases in 22 out of 24 patients in G2 compared to G1. While the LF power decreases in 21 out of 24 patients in G2 compared to G1. Comparing G3 to G1 the LF power decreases in 20 patients. The sum of the VLF and LF power is reduced in G2 in all 24 subjects compared to G1, and in 19 subjects in G3 compared to G1. CONCLUSIONS: The power spectral density of the HF shows increase in patients recorded on day 6 after operation compared to patients before the operation. The LF shows a decrease in G2 compared to G1. The results of G3 after 30 days of operation still show an increase of the HF power and a decrease in the LF power in most of the patients compared to their values before operation.

Transfusion indication predictive score: a proposed risk stratification score for perioperative red blood cell transfusion in cardiac surgery.

BACKGROUND AND OBJECTIVES: Red blood cell transfusion is known to be associated with increased morbidity and mortality in cardiac surgery. This study was performed to derive a score to predict that risk in our patients. MATERIALS AND METHODS: Clinical details of patients who underwent cardiac surgery at the Sultan Qaboos University Hospital over 5 years were reviewed. We used univariable and multivariable logistic regression to develop the score, the Hosmer-Lemeshow test for calibration, the receiver operator curve for discrimination and the bootstrap procedure for internal validation. RESULTS: The sample included 413 patients. The following were found to be statistically significant transfusion predictors (score given): cerebrovascular disease (4), use of aspirin or clopidogril within 7 days of surgery (3), non-elective surgery (2), haematocrit <35% (2), glucose-6-phosphate dehydrogenase (G6PD) deficiency (2), use of cardiopulmonary bypass (2), age > 60 years (1), diabetes mellitus (1) and male gender (-2). We classified the observations into three groups: group 1 with total score of <2, group 2 with total score of 2-5 and group 3 with total score of >5. The calculated probabilities of receiving transfusion were 42%, 63% and 91% for groups 1, 2 and 3 respectively. CONCLUSION: We derived a simple score that can be utilized to assess the need of blood transfusion in patients undergoing cardiac surgery. We are the first to report G6PD deficiency and history of cerebrovascular disease as predictors. We recommend prospective external validation of the proposed score on a larger cohort of patients.

[Surgical treatment of the combined heart, lung and liver hydatid disease].

Results of surgical treatment of 12 patients with the combined hydatid disease of heart and target organs (liver, lungs) are analyzed. Authors recommend echocardiography for all the patients with echinococcosis of target organs as a means of timely heart involvement diagnostics. Simultaneous surgery for the combined hydatid disease is recommended. The use of artificial circulation is reasonable for cardiac echinococcosis (n=66,7%) treatment, whereas pericardial hydatid cysts (n=33,3%) can be operated without such measures. Cyst perforations to the heart cavity should be considered a fatal complication of the disease. Intraoperative lethality achieved 25%.

[Detection and surgical treatment of induced ventricular tachycardia in postinfarction left ventricular aneurysm].

A clinical case of a patient aged 56 years with postinfarction left ventricular aneurysm not complicated with ventricular tachyarrhythmias is presented electrophysiological investigation. Left ventricular aneurysmectomy supplemented with endocardial cryodestruction was carried out. At electrophysiological investigation after surgery ventricular tachycardia could not be induced. In 2 years postoperatively no ventricular tachyarrhythmias were noted. The condition of the patient is satisfactory, corresponds to NYHA class I.

[Surgery of ventricular tachycardia in post-infarction left ventricular aneurysm]. / Chirurgie des tachycardies ventriculaires sur anévrismes ventriculaires gauches post-infarctus.

The treatment of post-infarction ventricular tachycardias with antiarrhythmic drug therapy, implantable automatic defibrillators, radiofrequency ablation, also includes different surgical procedures such as endocardial resection of the infarct scar, encircling endocardial ventriculotomy and endocardial cryoablation or thermoexclusion by laser. These procedures may be extensive or limited, guided or not by preoperative mapping. The aim of this review of the literature is to update our knowledge of these different surgical techniques and to define their indications.