Indications for the use of pacing pulmonary artery catheters in cardiac surgery

Right Heart Catheterization-Background, Physiological Basics, and Clinical Implications

The idea of right heart catheterization (RHC) grew in the milieu of modern thinking about the cardiovascular system, influenced by the experiments of William Harvey, which were inspired by the treatises of Greek philosophers like Aristotle and Gallen, who made significant contributions to the subject. RHC was first discovered in the eighteenth century by William Hale and was subsequently systematically improved by outstanding experiments in the field of physiology, led by Cournand and Dickinson Richards, which finally resulted in the implementation of pulmonary artery catheters (PAC) into clinical practice by Jeremy Swan and William Ganz in the early 1970s. Despite its premature euphoric reception, some further analysis seemed not to share the early enthusiasm as far as the safety and effectiveness issues were concerned. Nonetheless, RHC kept its significant role in the diagnosis, prognostic evaluation, and decision-making of pulmonary hypertension and heart failure patients. Its role in the treatment of end-stage heart failure seems not to be fully understood, although it is promising. PAC-guided optimization of the treatment of patients with ventricular assist devices and its beneficial introduction into clinical practice remains a challenge for the near future.

History of right heart catheterization: 100 years of experimentation and methodology development

The development of right heart catheterization has provided the clinician the ability to diagnose patients with congenital and acquired right heart disease, and to monitor patients in the intensive care unit with significant cardiovascular illnesses. The development of bedside pulmonary artery catheterization has become a standard of care for the critically ill patient since its introduction into the intensive care unit almost 40 years ago. However, adoption of this procedure into the mainstream of clinical practice occurred without prior evaluation or demonstration of its clinical or cost-effectiveness. Moreover, current randomized, controlled trials provide little evidence in support of the clinical utility of pulmonary artery catheterization in the management of critically ill patients. Nevertheless, the right heart catheter is an important diagnostic tool to assist the clinician in the diagnosis of congenital heart disease and acquired right heart disease, and moreover, when catheter placement is proximal to the right auricle (atria), this catheter provides an important and safe route for administration of fluids, medications, and parenteral nutrition. The purpose of this manuscript is to review the development of right heart catheterization that led to the ability to conduct physiologic studies in cardiovascular dynamics in normal individuals and in patients with cardiovascular diseases, and to review current controversies of the extension of the right heart catheter, the pulmonary artery catheter.

Transesophageal atrial pacing (TAP) for sinus bradycardia during coronary artery bypass grafting: comparison of TAP to intermittent bolus gallamine

OBJECTIVE

To assess the relative efficacy of a pacing esophageal stethoscope and intermittent boluses (40 mg) of gallamine in correcting sinus bradycardia (SB) during coronary artery surgery.

DESIGN

The study was prospective, randomized, and controlled.

SETTING

A community hospital.

PARTICIPANTS

Fifty patients scheduled for elective coronary artery surgery.

INTERVENTIONS

The patients were randomly allocated to receive treatment for an SB (less than 60 BPM) with either transesophageal atrial pacing (TAP) or gallamine.

MEASUREMENTS AND MAIN RESULTS

Heart rate, blood pressure, and systemic hemodynamics were measured. The electrocardiogram was monitored for rate, rhythm, and conduction abnormalities. Twenty-four of the 25 TAP patients could be paced at a rate of 70 BPM after SB. Cardiac index increased from 1.90 to 2.56 L/min/m2. In the gallamine group, heart rate was increased from 50 to 66 BPM, but cardiac index only increased to 2.2 L/min/m2, and 2 patients developed nodal rhythms. Eight of these patients had peak heart rates over 80 BPM, and two were over 90 BPM.

CONCLUSIONS

The ability to reliably and precisely control heart rate was superior with TAP compared with intermittent bolus dosing with gallamine.