PubMed Health⌕ Search

Biomedical subjects

George N Djaiani

Publications and source records attributed to George N Djaiani.

6 recordsLinked to original sources
PubMed2006

Aortic arch atheroma: stroke reduction in cardiac surgical patients.

Cardiac surgery is increasingly performed on elderly patients with extensive coronary artery abnormalities who have impaired left ventricular function, decreased physiologic reserve, and multiple comorbid conditions. Considerable numbers of these patients develop perioperative neurologic complications ranging from subtle cognitive dysfunction to more evident postoperative confusion, delirium, and, less commonly, clinically apparent stroke. Magnetic resonance imaging studies have elucidated that a considerable number of patients have new ischemic brain infarcts, particularly after conventional coronary artery bypass graft surgery. Mechanisms of cerebral injury during and after cardiac surgery are discussed. Intraoperative transesophageal echocardiography and epiaortic scanning for detection of atheromatous disease of the proximal thoracic aorta is paramount in identifying patients at high risk from neurologic injury. It is important to recognize that our efforts to minimize neurologic injury should not be limited to the intraoperative period. Particular efforts should be directed to temperature management, glycemia control, and pharmacologic neuroprotection extending into the postoperative period. Preoperative magnetic resonance angiography may be of value for screening patients with significant atheroma of the proximal thoracic aorta. It is likely that for patients with no significant atheromatous disease, conventional coronary artery revascularization is the most effective long-term strategy, whereas patients with atheromatous thoracic aorta may be better managed with beating heart surgery, hybrid techniques, or medical therapy alone. Patient stratification based on the aortic atheromatic burden should be addressed in future trials designed to tailor treatment strategies to improve long-term outcomes of coronary heart disease and reduce the risks of perioperative neurologic injury.

Animals↗
PubMed2003

Chronic exposure to nicotine does not prevent neurocognitive decline after cardiac surgery.

OBJECTIVE: To establish the association between smoking and cognitive decline in patients undergoing coronary artery bypass graft (CABG) surgery. DESIGN: Retrospective review. SETTING: Referral center for cardiothoracic surgery at a university hospital. PARTICIPANTS: Four hundred seventeen patients undergoing CABG surgery. INTERVENTIONS: Based on preoperative data, patients were divided into 2 groups: smokers (n = 185) and nonsmokers (n = 232). Patients who smoked half a pack of cigarettes per day within the last 2 years were identified as smokers, and patients who did not smoke were included in the nonsmoker group. Patients with less than a seventh grade education; an inability to read; or a history of one of the following medical conditions: prior stroke with residual deficit, psychiatric illness, renal disease (creatinine > 2.0 mg/dL), or active liver disease; or patients who quit smoking prior to surgery were excluded from the study. Both groups received similar anesthetic and surgical management. All patients received a battery of neurocognitive tests both preoperatively and 6 weeks after CABG surgery. Neurocognitive test scores were separated into 4 cognitive domains, with a composite cognitive index (the mean of the four domain scores) determined for each patient at every testing period. MEASUREMENTS AND MAIN RESULTS: The overall rate of cognitive decline at 6 weeks after surgery in smokers was 36.2%, whereas nonsmokers showed a deficit rate of 36.6%. Nonsmokers were significantly older and presented for surgery on average 6 years later than the smokers. Female sex represented a considerably larger proportion of patients in the nonsmoker group. Smokers had a higher prevalence of myocardial infarction. The univariate analysis of cognitive change at 6 weeks adjusted for age, baseline cognitive index, and education years showed no difference between the 2 groups. Sex, history of myocardial infarction, hypertension, stroke, transient ischemic attack, and duration of cardiopulmonary bypass did not contribute to the multivariate logistic regression model and were dropped from the final analysis. Significant multivariate predictors of neurocognitive dysfunction included age, left ventricular ejection fraction, baseline education level, and baseline cognitive index. CONCLUSIONS: This study confirmed previous findings that age, baseline cognitive function, years of education, and impaired left ventricular function are independent predictors of neurocognitive decline at 6 weeks after CABG surgery. Smoking is neither preventive nor causative of cognitive decline after CABG surgery.

Aged↗
PubMed2003

Intraoperative assessment of diastolic function: utility of echocardiography.

PURPOSE OF REVIEW: This review discusses the current and future applications of different echocardiographic modalities in evaluating diastolic function intraoperatively. RECENT FINDINGS: Normal diastolic function is required for optimal cardiac performance. There is sufficient evidence to support the significant prevalence of preoperative diastolic dysfunction and its incidence following cardiac surgery, however controversy still exists regarding the impact of diastolic dysfunction on adverse outcomes. Echocardiography provides a relatively safe, practical and noninvasive means to evaluate perioperative diastolic function, however conventional measures may be limited by the impact of changes in heart rate, rhythm and loading conditions. Newer echocardiographic modalities are reportedly less sensitive to acute changes in loading conditions, and may therefore complement the use of conventional echocardiographic techniques in the perioperative period. SUMMARY: The availability of effective technology for diagnosing the presence and progression of perioperative diastolic function should assist in the identification of high-risk cardiac surgical patients who may benefit from appropriate triaging and therapeutic intervention.

Journal Article↗
PubMed2003

Quantitative echocardiographic assessment of regional wall motion and left ventricular asynchrony with color kinesis in cardiac surgery patients.

UNLABELLED: Conventional echocardiographic interpretation of regional wall motion abnormalities is subjective and experience dependent. Delayed contraction in the ejection phase (tardokinesis) and regional systolic asynchrony, sensitive markers of myocardial ischemia, cannot be accurately assessed visually. We used color kinesis (CK), a technique that evaluates spatiotemporal patterns of endocardial motion, to objectively detect regional wall motion abnormalities in patients undergoing coronary bypass surgery, and we compared it with conventional assessment of grayscale images by less experienced reviewers; we used expert grading as the gold standard for comparisons. Quantitative CK analysis agreed more closely with expert grading than less experienced reviewers (kappa coefficients, 0.74 versus 0.52 and 0.5). Global tardokinesis, identified in 9 of 26 patients (2 with normal fractional area change), was associated with an increased index of systolic asynchrony. Regional tardokinesis was identified in 48 of 150 segments: 27 segments had a normal magnitude of wall motion, 18 were hypokinetic, and 3 were severely hypokinetic/akinetic. Mildly hypokinetic segments showed delayed systolic motion, whereas residual motion of severely hypokinetic/akinetic segments occurred in early systole, reflecting passive effects produced by adjacent myocardial contraction. Quantitative CK may be a useful supplement to visual assessment, particularly for less experienced readers. By diagnosing tardokinesis, common among cardiac surgical patients even with normal standard ejection phase indices, quantitative CK may improve the intraoperative detection of regional ischemic changes. IMPLICATIONS: Quantitative color kinesis allows for objective and sensitive intraoperative echocardiographic assessment of abnormal spatial and temporal patterns of regional ventricular wall motion, with potentially important implications for improving myocardial ischemia detection in patients undergoing cardiac surgery.

Cardiac Surgical Procedures↗
PubMed2002

Mitral flow propagation velocity identifies patients with abnormal diastolic function during coronary artery bypass graft surgery.

UNLABELLED: Flow propagation velocity (Vp) is a new method of assessing left ventricular (LV) diastolic (D) function that seems to be insensitive to heart rate and preload changes. We hypothesized that Vp <50 cm/s identifies patients with D dysfunction and that Vp provides an assessment of D function when standard Doppler techniques are uninterpretable. We conducted a prospective Doppler echocardiographic assessment of D function in 63 patients undergoing coronary artery bypass graft surgery. Doppler derivatives of mitral inflow and pulmonary vein flow profiles as well as isovolumic relaxation time were compared with Vp before and after cardiopulmonary bypass. A Valsalva maneuver was used to decrease preload. All patients with D dysfunction had Vp <50 cm/s. A Valsalva maneuver did not affect Vp. Vp remained a reliable measure of LV D function when mitral flow profiles could not be determined because of changes in heart rate and rhythm. LV filling patterns did not change significantly after cardiopulmonary bypass. We conclude that Vp is a simple measure of D function during coronary artery bypass graft surgery that correlates with standard, load-dependent Doppler echocardiographic techniques to identify D dysfunction. Vp <50 cm/s identifies abnormal D function in this patient population. IMPLICATIONS: Mitral propagation velocity (Vp) is a simple, reproducible measure of diastolic function during coronary artery bypass graft surgery that correlates with standard Doppler echocardiographic techniques to identify dysfunction in the setting of a rapid heart rate or variable preload. Vp <50 cm/s identifies abnormal diastolic function in this patient population.

Aged↗