Perioperative enoximone infusion improves cardiac enzyme release after CABG

Drug-Induced Atrial Fibrillation / Atrial Flutter

Drug-induced atrial fibrillation / flutter (DIAF) is a serious and potentially life-threatening complication of pharmacotherapy. Purpose of the work: systematization and analysis of scientific literature data on drugs, the use of which can cause the development of DIAF, as well as on epidemiology, pathophysiological mechanisms, risk factors, clinical picture, diagnosis and differential diagnosis, treatment and prevention of DIAF. Analysis of the literature has shown that many groups of drugs can cause the development of DIAF, with a greater frequency while taking anticancer drugs, drugs for the treatment of the cardiovascular, bronchopulmonary and central nervous systems. The mechanisms and main risk factors for the development of DIAF have not been finally established and are known only for certain drugs, therefore, this section requires further study. The main symptoms of DIAF are due to the severity of tachycardia and their influence on the parameters of central hemodynamics. For diagnosis, it is necessary to conduct an electrocardiogram (ECG) and Holter monitoring of an ECG and echocardiography. Differential diagnosis should be made with AF, which may be caused by other causes, as well as other rhythm and conduction disturbances. Successful treatment of DIAF is based on the principle of rapid recognition and immediate discontinuation of drugs (if possible), the use of which potentially caused the development of adverse drug reactions (ADR). The choice of management strategy: heart rate control or rhythm control, as well as the method of achievement (medication or non-medication), depends on the specific clinical situation. For the prevention of DIAF, it is necessary to instruct patients about possible symptoms and recommend self-monitoring of the pulse. It is important for practitioners to be wary of the risk of DIAF due to the variety of drugs that can potentially cause this ADR.

Body Perfusion during Adult Cardiopulmonary Bypass is Improved by Pulsatile flow with Intra-Aortic Balloon Pump

Purpose

To evaluate if the use of an intra-aortic balloon pump (IABP) during cardioplegic arrest improves body perfusion.

Methods

158 coronary artery bypass graft (CABG) patients were randomized to linear cardiopulmonary bypass (CPB) (n=71, Group A) or automatic 80 bpm intra-aortic ballon pump (IABP) induced pulsatile CPB (n=87, Group B). We evaluated hemodynamic response by Swan-Ganz catheter, inflammation by cytokines, coagulation and fibrinolysis, transaminase, bilirubin, amylase, lactate and renal function (estimated glomerular filtration rate (eGFR), creatinine, and incidence of renal insufficiency and failure).

Results

IABP induced Surplus Hemodynamic Energy was 15.8±4.9 mmHg, with higher mean arterial pressure during cross-clamping (p=0.001), and lower indexed systemic vascular resistances during cross-clamping (p=0.001) and CPB discontinuation (p=0.034). IL-2 and IL-6 were lower, while IL-10 proved higher in Group B (p<0.05). Group B showed lower chest drainage (p<0.05), transfusions (p<0.05), INR (p<0.05), and AT-III (p=0.001), together with higher platelets, aPTT (p<0.05), fibrinogen (p<0.05) and D-dimer (p<0.05). Transaminases, bilirubin, amylase, lactate were lower in Group B (p<0.05); eGFR was better in Group B from ITU-arrival to 48 hours, both in preoperative kidney disease Stages 1–2 (p<0.03) and Stage 3 (p<0.05), resulting in lower creatinine from ITU-arrival to 48 hours (p<0.03). Incidence of renal insufficiency (p=0.004) and need for renal replacement therapy (p=0.044) was lower in Group B Stage 3. Group B PaO2/FiO2 and lung compliance improved from aortic declamping to the first day (p<0.003) with shorter intubation time (p=0.01).

Conclusion

Pulsatile flow by IABP improves whole-body perfusion during CPB.

Myocardial protection by interferon-γ late preconditioning during cardiopulmonary bypass‑associated myocardial ischemia-reperfusion in pigs

The impact of interferon-γ (IFN-γ) late preconditioning on myocardial ischemia-reperfusion injury during cardiopulmonary bypass (CPB) and the underlying mechanism were investigated. Using a porcine model of myocardial ischemia-reperfusion injury during CPB with a 60-min aorta cross-clamp, 20 pigs (15±0.5 kg) were treated randomly with either a 1-ml (20,000 IU/kg) IFN-γ injection (IFN-γ group; n=10) or saline solution (control group; n=10) 24 h prior to CPB. Heart rate, blood pressure, left ventricular end-systolic pressure (LVESP), left ventricular end-diastolic pressure (LVEDP), creatine kinase isoenzyme-MB (CK-MB), and cardiac troponin I (cTnI) were measured before CPB, before aortic clamping, and at post-reperfusion intervals of 10, 30, 60 and 120 min. Heat shock protein 70 (HSP70), Mn-superoxide dismutase (Mn-SOD) and inducible nitric oxide synthase (iNOS) were measured by immunohistochemical staining in pre-CPB myocardial tissues. Myocardial cell apoptosis TUNEL measurement was assessed in samples obtained 60 min following reperfusion. Both groups exhibited no statistical differences in age, weight, gender and preoperative cardiac function, and worsened left ventricular function, and hemodynamic index reductions, and significant cTnI and CK-MB leakage was observed 10 and 30 min after reperfusion. At 10, 30 and 60 min following reperfusion, ventricular function and leakage of the IFN-γ group were significantly improved, and expression of HSP70, iNOS and Mn-SOD increased and myocardial cell apoptosis decreased. IFN-γ late preconditioning exhibited preventative effects on myocardial tissues in pigs during CPB surgery, likely due to increased HSP70, Mn-SOD and iNOS expression.

Drug-induced atrial fibrillation

INTRODUCTION

Atrial fibrillation (AF) is the most common arrhythmia and an important cause of hospitalization, morbidity, and mortality. A myriad of drugs can induce AF. However, drug-induced AF (DIAF) receives little attention. Thus, this review is an attempt to attract the attention on this adverse effect.

AREAS COVERED

Published reports of drug-induced AF (DIAF) are reviewed in this paper, from January 1974 to December 2011, using the PubMed/Medline database and lateral references.

EXPERT OPINION

In most cases, DIAF is paroxysmal and terminates spontaneously, but sometimes AF persists and it is necessary to perform a cardioversion to restore sinus rhythm and avoid progression to persistent AF. Because of the short duration of DIAF, in addition to physicians/patients not being knowledgeable about this side effect, the real incidence and clinical consequences of DIAF are presently unknown. DIAF is an increasing problem, as some widely prescribed drugs can present this adverse effect. The risk is expected to increase in the elderly and in patients with comorbidities. It is important that physicians understand the significance of DIAF, to increase the collaboration between cardiac and non-cardiac professionals, and to educate patients to make them aware of this adverse side effect.

Intraoperative behavior of arterial grafts in the elderly and the young: a flowmetric systematic analysis

Extensive arterial grafting (Art-CABG) in the elderly is still questioned due to the reduced life expectancy and the supposed higher periprocedural risk. Reports further demonstrated accelerated atherosclerosis of arterial grafts in the elderly, with hampered short-term and long-term results. We reviewed our experience of patients undergoing Art-CABG between January 2003 and January 2007, divided into two groups: the elderly (238 patients > or = 70 years; Group A) and the young (195 patients < or = 60 years; Group B). Transit time flowmetric (TTF) maximum and mean flow, pulsatility index (PI), and graft flow reserve (GFR) were compared. Hospital outcome was analyzed. Hospital mortality, need for intra-aortic balloon pump, troponin I, and echocardiographic segmental kinetics were comparable between the two groups (P = not significant [NS]). Stratifying patients for target vessels and type of arterial CABG, no differences in TTF results were recorded between the two groups either on-pump (P = NS) and off-pump (P = NS), both for the two internal mammary arteries (P = NS irrespective of the target vessel) and the radial artery conduits (P = NS irrespective of the target vessel). Although graft flow reserve was significantly recruited in all patients (P < 0.05 in young and elderly, either on-pump and off-pump, irrespective of the arterial conduit and the grafted vessel), GFR of all arterial grafts was comparable between elderly and young patients, either on-pump (P = NS) or off-pump (P = NS). Art-CABG showed similar TTF results in elderly and young patients, regardless of the arterial conduit, target vessel, or surgical technique employed. These functional results supported the reported survival benefit of arterial revascularization in the elderly.

Single versus sequential saphenous vein grafting of the circumflex system: a flowmetric study

OBJECTIVE

We sought to evaluate if patients with proximal critical circumflex (CX) lesions did better with single SV-CABG on the best obtuse marginal (OM), or with sequential SV-CABG on two OM branches.

DESIGN

Ninety patients were prospectively randomised to single SV-CABG on the best OM (sSV-CABG-45 patients; Group A) or to sequential SV-CABG on 2 OM (seqSV-CABG 45 patients; Group B). Transit-time flowmetry (TTF), and graft flow reserve were evaluated. Recurrent angina, acute myocardial infarction, readmission for coronary reintervention were defined "treatment failure" during follow-up.

RESULTS

SeqSV-CABG showed better intraoperative maximum (119.1+/-57.5 ml/min vs. sSV-CABG 62.4+/-29.6; p=0.001), mean (56.3+/-31.5 ml/min vs. 30.8+/-12.8; p=0.0001), minimum flow (22.8+/-9.2 ml/min vs. 11.8+/-8.9; p=0.001) and P.I. (0.71+/-0.4 vs.1.46+/-0.9; p=0.006). Graft flow reserve also proved to be higher (95.4+/-29.7 ml/min mean flow vs. sSV-CABG 42.3+/-15.2 ml/min mean flow; p=0.0001; flow reserve 1.72+/-0.99 vs 1.32+/-1.09; p=0.001) as well as freedom from treatment failure (97.5+/-0.5% vs 88.7+/-0.4%; p=0.05).

CONCLUSIONS

SeqSV-CABG showed higher TTF flows, with no incremental risk for perioperative morbidity. Higher flows and graft flow reserve may allow lower treatment failure at mid-term follow-up.

Perioperative Patency of Coronary Artery Bypass Grafting is Not Influenced by Off-Pump Technique

BACKGROUND

Some concerns have been raised about technical accuracy and quality of distal anastomoses in off-pump myocardial revascularization (OPCAB), which could affect graft patency.

METHODS

Transit-time flowmetric results and clinical, enzymatic, and echocardiographic findings from 201 consecutive isolated on-pump coronary artery bypass graft cases (cardiopulmonary bypass coronary artery bypass grafting; group A) were compared with 96 consecutive OPCAB (group B) cases performed at our institution between January 2003 and December 2004. Maximum, mean, minimum flow, and pulsatility index were compared, stratifying the two groups according to graft type and coronaries revascularized. Graft flow reserve was evaluated in patients undergoing preoperative intraaortic balloon pump during baseline conditions and at a 1 to 1 ratio of intraaortic balloon pump augmentation.

RESULTS

No differences were recorded between the two groups in hospital mortality, perioperative myocardial infarction, postoperative enzymatic leakage, echocardiographic recovery, or hospital stay (p = not significant). Off-pump coronary artery bypass and cardiopulmonary bypass coronary artery bypass grafting demonstrated similar intraoperative maximum (75.8 +/- 10.4 mL/min vs 82.3 +/- 15.8; p = 0.190), mean (50.1 +/- 13.3 vs 46.3 +/- 7.7; p = 0.420), minimum flow (12.7 +/- 5.3 vs 11.9 +/- 5.4; p = 0.811), and pulsatility index (2.9 +/- 0.2 vs 2.6 +/- 0.8; p = 0.360). After stratifying the population according to graft type, no differences were detected between the two groups in transit-time flowmetric results of left internal mammary artery, radial artery, and single and sequential saphenous vein grafts. A one to one ratio of intraaortic balloon pump augmentation did not result in any difference in graft flow reserve when left internal mammary artery (p = 0.699), radial artery (p = 0.066), and saphenous vein graft anastomoses (p = 0.772) were considered.

CONCLUSIONS

Off-pump coronary artery bypass grafting and cardiopulmonary bypass coronary artery bypass grafting demonstrated similar clinical, biochemical, and transit-time flowmetric results, as well as comparable graft flow reserve. These data exclude a lower anastomotic quality in off-pump coronary artery bypass grafting.

Cardiac troponins as biomarkers of drug- and toxin-induced cardiac toxicity and cardioprotection

Cardiac troponin T and I (cTnT, cTnI) are sensitive biochemical markers of myocardial cell necrosis and have been adopted as the gold standard tests for acute myocardial infarction. Subtle elevations in cTn above the detection limits of the currently available commercial assays confers poor prognosis. These markers are superior to classical enzyme markers of necrosis due to their cardiospecificity. The diagnosis of drug-induced cardiac toxicity using the classical enzymes is problematic due to the high elevations of these markers in skeletal muscle necrosis. cTnT and cTnI are now being adopted as sensitive biomarkers of drug-induced cardiac toxicity.