Todd J. Cohen

A Comparison of Active Compression-Decompression Cardiopulmonary Resuscitation with Standard Cardiopulmonary Resuscitation for Cardiac Arrests Occurring in the Hospital

BACKGROUNDnRecent studies have demonstrated improved cardiopulmonary circulation during cardiac arrest with the use of a hand-held suction device (Ambu CardioPump) to perform active compression-decompression cardiopulmonary resuscitation (CPR). The purpose of this study was to compare active compression-decompression with standard CPR during cardiac arrests in hospitalized patients.nnnMETHODSnAll patients over the age of 18 years who had a witnessed cardiac arrest while hospitalized at our center were enrolled in this trial; they were randomly assigned according to their medical-record numbers to receive either active compression-decompression or standard CPR. The study end points were the rates of initial resuscitation, survival at 24 hours, hospital discharge, and neurologic outcome. Compressions were performed according to the recommendations of the American Heart Association (80 to 100 compressions per minute; depth of compression, 3.8 to 5.1 cm [1.5 to 2 in.]; and 50 percent of the cycle spent in compression).nnnRESULTSnSixty-two patients (45 men and 17 women) with a mean age (+/- SE) of 68 +/- 2 years were entered into the trial. Sixty-two percent of the patients who underwent active compression-decompression were initially resuscitated, as compared with 30 percent of the patients who received standard CPR (P < 0.03); 45 percent of the patients who underwent active compression-decompression survived for at least 24 hours, as compared with 9 percent of patients who underwent standard CPR (P < 0.004). Two of the 62 study patients survived to hospital discharge; both were randomly assigned to receive active compression-decompression. Neurologic outcome, as measured by the Glasgow coma score, was better with active compression-decompression (8.0 +/- 1.3) than with standard CPR (3.5 +/- 0.3; P < 0.02).nnnCONCLUSIONSnIn this preliminary study, we found that, as compared with standard CPR, active compression-decompression CPR improved the rate of initial resuscitation, survival at 24 hours, and neurologic outcome after in-hospital cardiac arrest. Larger trials will be required to assess the potential benefit in terms of long-term survival.

Radiofrequency Catheter Ablation as a Primary Therapy for Treatment of Ventricular Tachycardia in a Patient After Repair of Tetralogy of Fallot

A 20‐year‐old man with previous surgical repair of tetralogy of Falht was admitted with hemodynamically significant ventricular tachycardia that was terminated witb cardioversion. He was found at electropbysiological study to bave easily inducible ventricular tacbycardia that was mapped to the rigbt ventricular outflow tract. Radiofrequency catheter ablation of tbe ventricular tacbycardia focus rendered tbe patients arrbytbmia noninducible. Tbis case represents a successful radiofrequency catbeter ablation of a ventricular tacbycardia focus associated witb tetralogy of Fallot repair.

Efficacy of pindolol for treatment of vasovagal syncope

The purpose of this study was to evaluate the efficacy, safety, and tolerance of pindolol as initial therapy for vasovagal syncope. Head-up tilt table testing (HUT) was performed on 192 patients for syncope or near-syncope of unknown cause. Forty-four (23%) patients had a positive HUT for vasovagal syncope, and 28 (64%) received oral pindolol as initial therapy. Three patients were lost to follow-up; of the remaining 25 patients (mean age 60 +/- 22 years), 15 were women, 14 had syncope, and 11 had near-syncope. At 14 +/- 6 months follow-up, 16 (64%) patients were without recurrence or side effects from pindolol. Of the 9 patients who stopped taking pindolol, 3 were switched to another regimen for recurrent symptoms, 2 stopped because of side effects, and 4 did not comply with the regimen. In conclusion, pindolol appears to be safe and effective as initial treatment for vasovagal syncope.

Vasovagal syncope as a cause of motor vehicle accidents

Motor vehicle accidents (MVAs) are the leading cause of death from all accidents in the United States.’ The medical causes include narcolepsy, seizure disorders, alcoholism, carotid sinus syndrome,2 and even tussive syncope.3 Vasovagal syncope has not been reported previously as a cause of MVAs. At North Shore University Hospital-Cornell University Medical College, 68 head-up tilt-table tests have been performed for unexplained syncope. Of those syncopal events, two involved patients who caused MVAs. The following case reports illustrate the importance of this diagnosis and the use of head-up tilt-table tests to determine the diagnosis and to guide therapy. Head-up tilttable tests were performed in the fasting state. Patients were connected to a standard 12-lead electrocardiographic (ECG) recorder for continuous monitoring and to a sphygmomanometer for blood pressure recordings. Baseline measurements of heart rate, blood pressure, and 12-lead ECG were obtained while the patient was in the supine position and after 5 minutes of rest. The table was then tilted to 60 degrees for 30 minutes or until syncope (defined as loss of consciousness). If no syncope occurred during the initial tilt, the patient was lowered to the supine position for 5 minutes. With the patient in the supine position, an intravenous isoproterenol infusion was then initiated at 0.5 pg/min and increased every 2 minutes (by 0.5 pglmin) until the patient’s heart rate increased by 20 % . After this was achieved, the patient was again tilted at 60 degrees for 10 minutes or until syncope occurred. Case 1. A 59-year-old man was admitted to the hospital after an MVA. The patient had no previous cardiac or neurologic history and while driving lost consciousness without preceding symptoms or seizure activity. This resulted in an MVA that fatally injured a pedestrian. The patient awoke with no memory of the MVA and reported no presyncopal symptoms. The patient was not incontinent, and no postictal state was noted. He denied having chest pain, palpitations, or shortness of breath. He was found by the paramedics to be oriented with a blood pressure 120/80 mm Hg, a heart rate of 50 beats/min, and a respiratory rate of 16

A simple electrocardiographic algorithm for detecting ventricular tachycardia.

The purpose of this study wus to determine whether a simple ECG algorithm could be developed for predicting susceptibility to ventricular tachyarrhythmias (VT) as defined by sustained spontaneous or inducible VT. Two different QT dispersion algorithms were determined by the difference between the longest and shortest QT interval measured in three orthogonal leads (I, aVF, V1; QTD3), and at least 11 of 12 leads (QTDl2) from the 12‐lead ECG. These QT dispersion algorithms were investigated (with and without the QRS duration from the 12‐lead EGG) and compared to the signal‐averaged ECG (SAEGG) in order to determine their sensitivity and specificity for detecting VT. Only patients who underwent SAECC and were referred for programmed electrical stimulation were included in this study. A positive SAECG was defined by filtered QRS duration > 114 ms, and/or low amplitude signal duration > 38 ms, and/or root mean square voltage in the last 40 ms of < 20 μV. Sixty patients were enrolled in this study with a mean age of 63 ± 2 years. Eifty‐five percent of the patients had coronary artery disease. A simple ECG algorithm consisting of the sum of QTD3 plus the QBS duration had a sensitivity and specificity of 90% and 63%. respectively, whereas the SAECG had a sensitivity and specificity of 60% and 63%. respectively (P = 0.022). We conclude that a simple EGG algorithm is more sensitive than the SAEGG for predicting VT. This algorithm combines two easily measured variables obtained from the 12‐lead EGG, and can easily be performed without expensive computer equipment.

Pseudorecurrence of paroxysmal supraventricular tachycardia after radiofrequency catheter ablation

Over an 11-month period (November 1992 to October 1993), 32 radiofrequency catheter ablations were performed for recurrent symptomatic supraventricular tachycardia in 17 patients with atrioventricular (AV) nodal reentry, 13 with AV reentry with an accessory pathway), and 2 with both AV and AV nodal reentry. Each patient underwent both diagnostic and therapeutic electrophysiologic study with radiofrequency catheter ablation in a single session. Twelve of the 32 patients had recurrent symptoms after catheter ablation. A repeat study was performed in 9 of the 12 patients. At 7.7 +/- 0.8 months (range 4 to 11) of follow-up only one patient had had a true symptomatic recurrence. Additional sessions of ablation cured this patient. We conclude that pseudorecurrence of paroxysmal supraventricular tachycardia is a common phenomenon in patients after radiofrequency catheter ablation. Follow-up electrophysiologic study demonstrates and helps differentiate pseudo from true paroxysmal supraventricular tachycardia recurrence.

Development of an Interactive Computer‐Guided Method for Radiofrequency Catheter Ablation of Ventricular Tachycardia

The purpose of this study was to develop a simple computer‐guided approach to localizing ventricular tachycardias during ventricular mapping. Six patients with sustained monomorphic ventricular tachycardia were connected to a 32‐lead computer body surface mapping system. Isoarea maps of induced ventricular tachycardia were recorded. Then a pacing probe was placed in either the right or left ventricle, and maps were generated from a variety of sites. Differences between ventricular tachycardia and pace map maxima X,Y coordinates were utilized to guide catheter manipulation and localization. In 6 of 6 patients (100%) this method appeared to provide a systematic approach to ventricular tachycardia localization. Computer‐generated correlations as well as the X,Y coordinates of the QRS isoarea maxima were used to determine proximity to the ventricular tachycardia foci and direct catheter manipulation. In the next three patients this method was applied prospectively to help guide catheter manipulation during ventricular tachycardia (two right ventricular outflow tract tachycardias, and one left ventricular tachycardia). After a mean of 4.0 ± 1.7 radiofrequency applications, ventricular tachycardia was no longer inducible, and at 7 ± 0 months follow‐up there have been no arrhythmia recurrences. We conclude that online computerized body surface mapping can assist in localizing ventricular tachycardia. Differences in maxima during pace maps and in‐situ ventricular tachycardias can help with catheter manipulation as well as with more precise identification of focal tachycardias. This technique appears to hold the promise of a simple computer‐guided method that may facilitate radiofrequency catheter ablation.

The "EP manager": a database management system for electrophysiology practice

A database program developed specifically for tracking all data collected during routine electrophysiology practice (EP) is described. The program is written in Filemaker Pro, a flat-file Macintosh based system. The database provides a standard of data entry and data integrity, easy retrieving and reporting clinical data. It assists in clinical decision making and improves the quality of care of patients as well as provides a historical data for future research and analysis.<<ETX>>

Evaluation of vasovagal syncope with body surface mapping during head-up tilt-table testing

Abstract In conclusion, during vasovagal syncope we observed an increase in the QRST isoarea gradient (reflecting greater uniformity of repolarization), possibly due to changes in autonomic tone. In contrast, we observed a decrease in the QRST isoarea gradient (increased disparity of repolarization) in patients without vasovagal syncope during HUT. Future research should examine the clinical use of BSM as an early predictor of vasovagal syncope before symptom onset during HUT, thus limiting patient discomfort.