Perioperative Optimization of the Cardiac Surgical Patient.

Perioperative optimization of cardiac surgical patients is imperative to reduce complications, utilize health care resources efficiently, and improve patient recovery and quality of life. Standardized application of evidence-based best practices can lead to better outcomes. Although many practices should be applied universally to all patients, there are also opportunities along the surgical journey to identify patients who will benefit from additional interventions that will further ameliorate their recovery. Enhanced recovery programs aim to bundle several process elements in a standardized fashion to optimize outcomes after cardiac surgery. A foundational concept of enhanced recovery is attaining a better postsurgical end point for patients, in less time, through achievement and maintenance in their greatest possible physiologic, functional, and psychological state. Perioperative optimization is a broad topic, spanning multiple phases of care and involving a variety of medical specialties and nonphysician health care providers. In this review we highlight a variety of perioperative care topics, in which a comprehensive approach to patient care can lead to improved results for patients, providers, and the health care system. A particular focus on patient-centred care is included. Although existing evidence supports all of the elements reviewed, most require further improvements in implementation, as well as additional research, before their full potential and usefulness can be determined.

Bayés' syndrome: the association between interatrial block and supraventricular arrhythmias.

The past few years have given rise to extensive research on atrial conduction disorders and their clinical relevance. Most notably, an association between interatrial block and supraventricular arrhythmias has been discovered. This disorder, recently termed 'Bayés' syndrome', has important clinical implications. In this article, the authors review normal atrial conduction and associated disorders. A particular focus is placed on Bayés' syndrome and the relationship between interatrial block and supraventricular arrhythmias in different clinical scenarios. The report also outlines the current progress in the study of this syndrome and highlights areas requiring further investigation.

Left ventricular filling pressure in male patients with type 2 diabetes and normal versus low total testosterone levels.

BACKGROUND: Heart failure is a common complication of diabetes characterized by an elevation in left ventricular filling pressures (LVF) that often develops in the absence of clinical symptoms. Diastolic dysfunction in the setting of low total testosterone (LTT) occurs through changes in the regulation of peripheral hemodynamics. LTT is highly prevalent among individuals with type 2 diabetes. The aim of this study was to compare LVF in male diabetic patients with no structural heart disease and normal serum testosterone levels vs. those with LTT. METHODS: Type 2 diabetic patients were assessed using tissue Doppler imaging to evaluate LVF and other conventional parameters of diastolic function. The E/e' ratio was used to estimate LVF through the ratio of peak passive trans-mitral left ventricular inflow velocity to the peak passive inflow velocity at the lateral mitral annulus. Patients were assigned to one of two groups based upon their total testosterone levels. Group A consisted of low (< 3.5 ng/mL) testosterone levels and group B consisted of normal (> 3.5 ng/mL) testosterone levels. RESULTS: A total of 148 male patients were included: group A--47 (32%) patients; group B--101 (68%) patients, respectively. Mean age was 58 ± 5.8 years and mean time of diabetes evolution was 7 ± 3.1 years. There were no significant differences between the groups regarding age, duration of diabetes evolution, hypertension, weight, heart rate, body mass index, and echocardiographic parameters. The E/e' ratio for group A was 8.05 ± 1.9 vs. 6.1 ± 1.7 for group B (p < 0.0001). The E/A ratio was 0.94 ± 0.10 vs. 1.19 ± 0.12 (p = 0.01), deceleration time 242 ± 7.4 ms vs. 205 ± 9 ms (p = 0.026) and systolic pulmonary artery pressure 27 ± ± 2.2 mm Hg vs. 22 ± 1.7 mm Hg (p = 0.11). CONCLUSIONS: Patients with type 2 diabetes and LTT have a higher E/e' ratio demonstrating a pre-clinical increase in LVF when compared to similar patients with normal testosterone levels. This finding is independent of time of diabetes evolution, hypertension and other echocardiographic parameters.

Erythromycin, QTc interval prolongation, and torsade de pointes: Case reports, major risk factors and illness severity.

OBJECTIVES: Erythromycin is a macrolide antibiotic that is widely used for various infections of the upper respiratory tract, skin, and soft tissue. Similar to other macrolides (clarithromycin, azithromycin), erythromycin has been linked to QTc interval prolongation and torsade de pointes (TdP) arrhythmia. We sought to identify factors that link to erythromycin-induced/associated QTc interval prolongation and TdP. METHODS AND RESULTS: In a critical evaluation of case reports, we found 29 cases: 22 women and 7 men (age range 18-95 years). With both oral and intravenous erythromycin administration, there was no significant relationship between dose and QTc interval duration in these cases. Notably, all patients had severe illness. Other risk factors included female sex, older age, presence of heart disease, concomitant administration of either other QTc prolonging drugs or agents that were substrates for or inhibitors of CYP3A4. Most patients had at least two risk factors. CONCLUSIONS: On the basis of case report evaluation, we believe that major risk factors for erythromycin-associated TdP are female sex, heart disease and old age, particularly against a background of severe illness. Coadministration of erythromycin with other drugs that inhibit or are metabolized by CYP3A4 or with QTc prolonging drugs should be avoided in this setting.

Multifactorial QT Interval Prolongation and Takotsubo Cardiomyopathy.

A 71-year-old woman collapsed while working as a grocery store cashier. CPR was performed and an AED revealed torsades de pointes (TdP). She was subsequently defibrillated resulting in restoration of sinus rhythm with a QTc interval of 544 msec. Further evaluation revealed a diagnosis of Takotsubo Cardiomyopathy (TCM) contributing to the development of a multifactorial acquired long QT syndrome (LQTS). The case highlights the role of TCM as a cause of LQTS in the setting of multiple risk factors including old age, female gender, hypokalemia, and treatment with QT prolonging medications. It also highlights the multifactorial nature of acquired LQTS and lends support to growing evidence of an association with TCM.

The use of fontaine leads in the diagnosis of arrhythmogenic right ventricular dysplasia.

We report a case of a 68-year-old man admitted to the emergency department with syncope preceded by rapid palpitations. His admission ECG demonstrated a sustained ventricular tachycardia (VT) originating from the right ventricular outflow tract (RVOT). This report highlights the importance of distinguishing ventricular tachycardia caused by arrhythmogenic right ventricular dysplasia (ARVD) from the more benign idiopathic RVOT-VT. Furthermore, we demonstrate the utility of the Fontaine leads placement in increasing the sensitivity for uncovering epsilon waves, a highly specific electrocardiographic feature that increases diagnostic accuracy in patients with ARVD.

Torsades de pointes following clarithromycin treatment.

A 75-year-old woman presenting with pre-syncope, shortness of breath and nausea was admitted to the emergency department following treatment with clarithromycin. Shortly after admission she developed a prolonged QT interval leading to torsades de pointes (TdP) and cardiac arrest. She was successfully cardioverted and clarithromycin was discontinued resulting in restoration of her usual QT interval. This case is an example of acquired long QT syndrome; a disorder that can be precipitated by macrolide antibiotics such as clarithromycin. Additional risk factors present in this case include: female gender, old age, heart disease, hypokalemia and hypomagnesemia. In this manuscript we comprehensively review past cases of clarithromycin-induced long QT syndrome (LQTS) and discuss them within the context of this case.

Clarithromycin, QTc interval prolongation and torsades de pointes: the need to study case reports.

BACKGROUND: The manufacturers of clarithromycin sought a drug similar in efficacy to erythromycin but with a superior side-effect profile. They generally achieved this outcome, but postmarketing findings identified a series of reports linking clarithromycin to QTc interval prolongation and torsades de pointes (TdP) ultimately leading to a Black Box Warning. We sought to clarify risk factors associated with TdP among case reports of patients receiving clarithromycin linked to QTc interval prolongation and TdP. METHODS AND RESULTS: In a detailed literature search, we found 15 women, five men, and one boy meeting our search criteria. Among the 17 adults with reported clarithromycin dose and concurrent QTc interval measurement, we found no statistically significant relationship between clarithromycin dose and QTc interval duration. This did not change for the adults who developed TdP. Among adults, major risk factors were female sex (15), old age (11) and heart disease (17). A total of eight adult subjects had all three major risk factors and 14 of the 20 adults had at least two major risk factors. All adult subjects had at least two risk factors besides clarithromycin. A total of four of the 20 adults received cisapride and three received disopyramide. Three adults were considered to suffer from some aspect of the congenital long QT syndrome. CONCLUSIONS: We believe that the risk factor description for this drug should be refined to emphasize the major risk factors of (1) female sex, (2) old age and (3) heart disease.