Sinus bradycardia (SB) or atrioventricular junctional rhythm (AVJR) may produce circulatory insufficiency in anesthetized surgical patients, especially those with cardiovascular disease. Chronotropic drugs have been the preferred initial treatment, except when epicardial pacing is available. Alternative methods include transvenous or transcutaneous pacing. Drugs may be ineffective or have undesirable effects. Transvenous pacing is time consuming and risky, and transcutaneous pacing is not universally applicable or effective. Transesophageal atrial pacing (TAP) lacks these disadvantages, but unavailability of equipment and unfamiliarity with the method has discouraged widespread use. Feasibility of TAP as prophylaxis for intraoperative SB or AVJR was tested with approved or investigational devices in 200 anesthetized surgical patients, not necessarily with cardiovascular disease or having cardiac surgery. Of these, 84 later had incidental SB ≤60 beats/min, and 23 of these 84 had SB ≤50 beats/min. Thirteen patients had AVJR (72 ± 4 beats/ min; mean ± SEM). TAP at 80 beats/min for SB, or at a rate sufficient to overdrive AVJR, was effective initial treatment in all patients. Respective average increases in systolic, diastolic, and mean arterial pressures for patients with SB ≤60 beats/ min were 14,12, and 14 mmHg (P < .001); for SB ≤50 beats/min 22,17, and 19 mmHg (P < .001); and for AVJR 23 (P < .01), 9 (NS), and 15 mmHg (P < .05), respectively. For patients with cardiac output measurements the average increase for SB ≤60 beats/min was 1.4 L/min (N = 13, P < .01); for SB ≤50 beats/min 1.8 L/min (N = 7, P < .05); and for AVJR was 2.6 L/mmin (N = 2). There were no apparent complications of TAP as prophylaxis or treatment for SB or AVJR. TAP has been shown to be a safe, simple, rapid, and effective method for prophylaxis and initial treatment of intraoperative SB or AVJR. Potential advantages of TAP over drugs are discussed.

Propofol is an intravenous (IV) drug recently introduced into the United States for induction and maintenance of anesthesia. In spite of extensive laboratory evaluation, it is not possible to predict all the potential side effects that might be associated with a new drug. Because malignant hyperthermia (MH) remains a serious and potentially life-threatening complication of anesthesia, all new anesthetic drugs should be considered potential triggering drugs until proven otherwise. We report the use of IV propofol for the induction and maintenance of general anesthesia in an MH patient and review the literature on this subject.

Sinus bradycardia (SB) and atrioventricular junctional rhythm (AVJR) commonly cause circulatory insufficiency in anesthetized surgical patients. Treatment is usually with drugs, which can be ineffective or have adverse effects. Cardiac pacing might be preferred, but the transvenous or epicardial routes are too invasive for routine use, and transcutaneous pacing fails to preserve atrial transport function. Transesophageal atrial pacing (TAP) lacks these disadvantages, yet unavailability of inexpensive products has prevented more widespread use. Therefore, a pacing esophageal stethoscope (PES) fabricated by addition of bipolar electrodes to disposable esophageal stethoscopes routinely used for intraoperative monitoring, was evaluated in 100 anesthetized adults. TAP thresholds (10-msec pulses) and hemodynamic effects of TAP as treatment for incidental SB (< or = 60 beats/min) or AVJR were determined. Minimum TAP thresholds (mean +/- standard error) in 48 males were 7.3 +/- 0.3 mA and in 51 females were 8.5 +/- 0.4 mA. Corresponding inferior alveolar ridge-to-electrode distances were 32.5 +/- 0.2 and 30.4 +/- 0.2 cm. For 48 patients with SB < or = 60 beats/min (54 +/- 1 beats/min), TAP (81 +/- 1 ppm) produced average 15, 11, and 14 mmHg increases in systolic, diastolic, and mean arterial pressure, respectively (P < 0.001). For 11 patients with AVJR (71 +/- 5 beats/min), TAP (92 +/- 3 ppm) produced average 23 and 15 mmHg increases in systolic and mean arterial pressure, respectively (P < 0.05). There were no apparent complications of TAP. TAP with a PES appears practical, safe, and effective for prophylaxis and treatment of SB or AVJR in anesthetized surgical patients.

Transesophageal atrial pacing (TAP) with the use of standard, thermistor-equipped, esophageal stethoscopes, modified for pacing by incorporation of a 4-French, bipolar TAP probe (pacing esophageal stethoscope [PES]), was evaluated in 100 adult patients under general anesthesia. A commercially available TAP pulse generator supplied 10-ms pulses with current variable between 0 and 40 mA. Pacing distances (in centimeters) were measured from the infraalveolar ridge to midway between PES electrodes (1.5-cm interelectrode distance). Pacing thresholds (milliamperes) were measured at the point of a maximum-amplitude P-wave (PMAX) in the bipolar esophageal electrogram and points 1 cm proximal or 1, 2, or 3 cm distal to PMAX. TAP (70-100 beats per min) was used for sinus bradycardia less than or equal to 60 beats per min (36 patients) or atrioventricular (AV) junctional rhythm (2 patients) and blood pressure changes with TAP documented. In male patients (n = 49), PMAX was 32.7 +/- 0.3 cm (mean +/- SE) and minimum pacing threshold 5.1 +/- 0.4 mA (range, 1-13 mA) at 33.6 +/- 0.3 cm (range, 30-37 cm). In female patients (n = 51), PMAX was 30.4 +/- 0.4 cm and minimum pacing threshold 4.4 +/- 0.4 mA (range, 2-14 mA) at 31.1 +/- 0.4 cm (range, 26-40 cm). TAP produced an average 13-16 mmHg increase in systolic, diastolic, or mean arterial pressure in patients with sinus bradycardia or AV junctional rhythm. There were no subjective patient complaints (epigastric discomfort, dysphagia) that could be attributed to TAP; objective evaluation (esophagoscopy) was not performed.(ABSTRACT TRUNCATED AT 250 WORDS)