HAEMODYNAMIC RESPONSES TO INDUCTION OF ANAESTHESIA USING MIDAZOLAM IN CARDIAC SURGICAL PATIENTS

The cardiovascular effects of midazolam 0.2 mg kg^–1 l.v.were studied during the induction of anaesthesia in 16 premedicatedpatients subjected to cardiac surgery. In eight patients withcoronary artery disease in whom global resting left ventricularfunction was normal the haemodynamic changes were small andobservations on arterial pressure, cardiac index, stroke index,cardiac filling pressures, systemic and pulmonary vascular resistanceappeared to parallel those accompanying deep sleep in healthyvolunteers. In eight patients with valvular heart disease andhaemodynamic evidence of moderately impaired cardiac performance,pump function during induction with midazolam was maintained,probably as a result of the tendency towards a decrease in systemicvascular resistance. Midazolam appears to be a valuable alternativeto conventional induction agents without adverse effects onthe cardiovascular system.     

Rationale and Design of the OPTION Study: Optimal Antitachycardia Therapy in ICD Patients without Pacing Indications

Background: Implantable cardioverter‐defibrillators (ICDs) represent the treatment of choice for primary and secondary prevention of sudden cardiac death but ICD therapy is also plagued by inappropriate shocks due to supraventricular tachyarrhythmias. Dual‐chamber (DC) ICDs are considered to exhibit an enhanced discrimination performance in comparison to single‐chamber (SC) ICDs, which results in reduction of inappropriate detections in a short‐ to mid‐term follow‐up. Comparative data on long‐term follow‐up and especially on inappropriate shocks are limited. Methods: The aim of the OPTION study is to assess whether an optimized treatment with DC ICDs improves patient outcome and decreases the rate of inappropriate shocks in comparison to SC ICDs. DC ICD therapy optimization is achieved by optimal customizing of antitachycardia therapy parameters, activation of discrimination algorithms, antitachycardia pacing in the slow ventricular tachycardia zone, and avoidance of right ventricular pacing with the SafeR algorithm mode. The OPTION study, a prospective, multicenter, randomized, single‐blinded, parallel study, will randomize 450 patients on a 1:1 allocation to either an SC arm with backup pacing at VVI 40 beats per minute (bpm) or to the DC arm with SafeR pacing at 60 bpm. Patients will be followed for 27 months. Primary outcome measure is the time to first occurrence of inappropriate shock and a combined endpoint of cardiovascular morbidity and all‐cause mortality. Conclusion: The study will evaluate the relative performance of DC in comparison to SC ICDs in terms of inappropriate shock reduction and patient outcome. (PACE 2010; 33:1141–1148)