Gordon A. Ewy

ACC/AHA 2004 guideline update for coronary artery bypass graft surgery: summary article. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Update the 1999 Guidelines for Coronary Artery Bypass Graft Surgery).

The American College of Cardiology (ACC)/American Heart Association (AHA) Task Force on Practice Guidelines regularly reviews existing guidelines to determine when an update or full revision is needed. This process gives priority to areas where major changes in text, particularly recommendations, are mentioned on the basis of new understanding of evidence. Minor changes in verbiage and references are discouraged. The ACC/AHA Guidelines for Coronary Artery Bypass Graft Surgery published in 1999 have now been updated. The full-text guidelines incorporating the updated material are available on the Internet (www.acc.org or www.americanheart.org) in both a version that shows the changes from the 1999 guidelines in track changes mode, with strike-through indicating deleted text and underlining indicating new text, and a “clean” version that fully incorporates the changes. This article describes the major areas of change reflected in the update in a format that we hope can be read and understood as a stand-alone document. Please note we have changed the table of contents headings in the 1999 guidelines from roman numerals to unique identifying numbers. Interested readers are referred to the full-length Internet version to completely understand the context of these changes. Classification of Recommendations and Level of Evidence are expressed in the ACC/AHA format as follows: ### Classification of Recommendations ### Level of Evidence

ACC/AHA Guideline Update for Perioperative Cardiovascular Evaluation for Noncardiac Surgery—Executive Summary A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Update the 1996 Guidelines on Perioperative Cardiovascular Evaluation for Noncardiac Surgery)

These guidelines represent an update of those published in 1996 and are intended for physicians who are involved in the preoperative, operative, and postoperative care of patients undergoing noncardiac surgery. They provide a framework for considering cardiac risk of noncardiac surgery in a variety of patient and surgical situations. The overriding theme of these guidelines is that preoperative intervention is rarely necessary simply to lower the risk of surgery unless such intervention is indicated irrespective of the preoperative context. The purpose of preoperative evaluation is not simply to give medical clearance but rather to perform an evaluation of the patient’s current medical status; make recommendations concerning the evaluation, management, and risk of cardiac problems over the entire perioperative period; and provide a clinical risk profile that the patient, primary physician, anesthesiologist, and surgeon can use in making treatment decisions that may influence short- and long-term cardiac outcomes. The goal of the consultation is to identify the most appropriate testing and treatment strategies to optimize care of the patient, provide assessment of both short- and long-term cardiac risk, and avoid unnecessary testing in this era of cost containment. ### A. Development of Guidelines These guidelines are based on an update of a Medline, EMBASE, Cochrane library, and Best Evidence search of the English literature from 1995 through 2000, a review of selected journals, and the expert opinions of 12 committee members representing various disciplines of cardiovascular care, including general cardiology, interventional cardiology, noninvasive testing, vascular medicine, vascular surgery, anesthesiology, and arrhythmia management. As a result of these searches, more than 400 relevant new articles were identified. In addition, draft guidelines were submitted for critical review and amendment to the executive officers representing the American College of Cardiology (ACC) and the American Heart Association (AHA). A large proportion of the data used to develop these guidelines are …

Minimally Interrupted Cardiac Resuscitation by Emergency Medical Services for Out-of-Hospital Cardiac Arrest

CONTEXT Out-of-hospital cardiac arrest is a major public health problem. OBJECTIVE To investigate whether the survival of patients with out-of-hospital cardiac arrest would improve with minimally interrupted cardiac resuscitation (MICR), an alternate emergency medical services (EMS) protocol. DESIGN, SETTING, AND PATIENTS A prospective study of survival-to-hospital discharge between January 1, 2005, and November 22, 2007. Patients with out-of-hospital cardiac arrests in 2 metropolitan cities in Arizona before and after MICR training of fire department emergency medical personnel were assessed. In a second analysis of protocol compliance, patients from the 2 metropolitan cities and 60 additional fire departments in Arizona who actually received MICR were compared with patients who did not receive MICR but received standard advanced life support. INTERVENTION Instruction for EMS personnel in MICR, an approach that includes an initial series of 200 uninterrupted chest compressions, rhythm analysis with a single shock, 200 immediate postshock chest compressions before pulse check or rhythm reanalysis, early administration of epinephrine, and delayed endotracheal intubation. MAIN OUTCOME MEASURE Survival-to-hospital discharge. RESULTS Among the 886 patients in the 2 metropolitan cities, survival-to-hospital discharge increased from 1.8% (4/218) before MICR training to 5.4% (36/668) after MICR training (odds ratio [OR], 3.0; 95% confidence interval [CI], 1.1-8.9). In the subgroup of 174 patients with witnessed cardiac arrest and ventricular fibrillation, survival increased from 4.7% (2/43) before MICR training to 17.6% (23/131) after MICR training (OR, 8.6; 95% CI, 1.8-42.0). In the analysis of MICR protocol compliance involving 2460 patients with cardiac arrest, survival was significantly better among patients who received MICR than those who did not (9.1% [60/661] vs 3.8% [69/1799]; OR, 2.7; 95% CI, 1.9-4.1), as well as patients with witnessed ventricular fibrillation (28.4% [40/141] vs 11.9% [46/387]; OR, 3.4; 95% CI, 2.0-5.8). CONCLUSIONS Survival-to-hospital discharge of patients with out-of-hospital cardiac arrest increased after implementation of MICR as an alternate EMS protocol. These results need to be confirmed in a randomized trial.

Myocardial Necrosis from Direct Current Countershock Effect of Paddle Electrode Size and Time Interval Between Discharges

The effect of varying both paddle electrode size and the time interval between direct current countershock on myocardial necrosis was studied. Forty-two dogs were divided into seven groups of six dogs each. All dogs were given ten consecutive, 240 watt-second countershocks (delivered energy into a 50 ohm load). Three groups were shocked with paddle electrode diameters of 8.0 cm (standard electrodes), two groups with paddle electrode diameters of 12.8 cm (large electrodes), and two groups with paddle electrode diameters of 4.3 cm (small electrodes). The time intervals between discharges in the groups shocked with the standard electrodes were 15 seconds, one minute, and three minutes. The time interval between discharges in the groups shocked with small and large electrodes was 15 seconds and three minutes. Myocardial necrosis was quantitated by precordial electrocardiographic mapping recorded minutes after, and by gross and microscopic examination of the hearts four days after direct current countershock.When the time interval between discharges was shorter, myocardial necrosis was greater. When the time interval between discharges was constant, more necrosis was produced with smaller-sized paddle electrodes. It is concluded that large paddle electrodes should be used for delivering direct current countershocks, and that during elective cardioversion, consecutive discharges should be delivered at time intervals greater than three minutes.

Interruptions of Chest Compressions During Emergency Medical Systems Resuscitation

Background—Survival after nontraumatic out-of-hospital (OOH) cardiac arrest in Tucson, Arizona, has been flat at 6% (121/2177) for the decade 1992 to 2001. We hypothesized that interruptions of chest compressions occur commonly and for substantial periods during treatment of OOH cardiac arrest and could be contributing to the lack of improvement in resuscitation outcome. Methods and Results—Sixty-one adult OOH cardiac arrest patients treated by automated external defibrillator (AED)–equipped Tucson Fire Department first responders from November 2001 through November 2002 were retrospectively reviewed. Reviews were performed according to the code arrest record and verified with the AED printout. Validation of the methodology for determining the performance of chest compressions was done post hoc. The median time from “9-1-1” call receipt to arrival at the patient’s side was 6 minutes, 27 seconds (interquartile range [IQR, 25% to 75%], 5 minutes, 24 seconds, to 7 minutes, 34 seconds). An additional 54 seconds (IQR, 38 to 74 seconds) was noted between arrival and the first defibrillation attempt. Initial defibrillation shocks never restored a perfusing rhythm (0/21). Chest compressions were performed only 43% of the time during the resuscitation effort. Although attempting to follow the 2000 guidelines for cardiopulmonary resuscitation, chest compressions were delayed or interrupted repeatedly throughout the resuscitation effort. Survival to hospital discharge was 7%, not different from that of our historical control (4/61 versus 121/2177; P=0.74). Conclusions—Frequent interruption of chest compressions results in no circulatory support during more than half of resuscitation efforts. Such interruptions could be a major contributing factor to the continued poor outcome seen with OOH cardiac arrest.

ACC/AHA guideline update for perioperative cardiovascular evaluation for noncardiac surgery - Executive summary: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to update the 1996 guidelines on perioperative cardiovascular evaluation for noncardiac surgery)

Table of ContentsI. IntroductionA. Development of GuidelinesB. General ApproachC. Preoperative Clinical EvaluationII. Further Preoperative Testing to Assess Coronary RiskA. Clinical MarkersB. Functional CapacityC. Surgery-Specific RiskIII. Management of Specific Preoperative Cardiovascular Condition

Bystander cardiopulmonary resuscitation. Is ventilation necessary

BackgroundPrompt initiation of bystander cardiopulmonary resuscitation (CPR) improves survival. Basic life support with mouth-to-mouth ventilation and chest compressions is intimidating, difficult to remember, and difficult to perform. Chest compressions alone can be easily taught, easily remembered, easily performed, adequately taught by dispatcher-delivered telephone instruction, and more readily accepted by the public. The principal objective of this study was to evaluate the need for ventilation during CPR in a clinically relevant swine model of prehospital witnessed cardiac arrest. Methods and ResultsThirty seconds after ventricular fibrillation, swine were randomly assigned to 12 minutes of chest compressions plus mechanical ventilation (group A), chest compressions only (group B), or no CPR (group C). Standard advanced cardiac life support was then provided. Animals successfuly resuscitated were supported for 2 hours in an intensive care setting, and then observed for 24 hours. All 16 swine in groups A and B were successfully resuscitated and neurologically normal at 24 hours, whereas only 2 of 8 group C animals survived for 24 hours (P<.001, Fishers exact test). One of the 2 group C survivors was comatose and unresponsive ConclusionsIn this swine model of witnessed prehospital cardiac arrest, the survival and neurological outcome data establish that prompt initiation of chest compressions alone appears to be as effective as chest compressions plus ventilation and that both techniques of bystander CPR markedly improve outcome compared with no bystander CPR.

Bedside cardiovascular examination in patients with severe chronic heart failure: Importance of rest or inducible jugular venous distension

OBJECTIVES The aim of this study was to determine the sensitivity, specificity and utility of the cardiovascular examination in predicting cardiac hemodynamics in patients with advanced chronic congestive heart failure. BACKGROUND Although the physical signs of acute left heart failure have been shown to correlate relatively well with cardiac hemodynamics, their reliability in estimating hemodynamics in patients with chronic heart failure has recently been questioned. METHODS We prospectively recorded the history, cardiovascular physical signs present at bedside examination and the hemodynamic measurements obtained at right heart catheterization in 52 patients with chronic congestive heart failure undergoing in-hospital evaluation for possible heart transplantation. In addition, we obtained chest radiographs and multigated nuclear scans for the evaluation of left ventricular function. RESULTS Pulmonary rales, a left ventricular third heart sound, jugular venous distension and the abdominojugular test, when positive, indicated higher right heart pressures and lower measures of cardiac performance. The presence of jugular venous distension, at rest or inducible, had the best combination of sensitivity (81%), specificity (80%) and predictive accuracy (81%) for elevation of the pulmonary capillary wedge pressure (> or = 18 mm Hg). Furthermore, in this population sample, the probability of an elevated wedge pressure was 0.86 when either variable was present. CONCLUSIONS The bedside cardiovascular examination in the patient with chronic heart failure is extremely useful in identifying patients with elevation of right and left heart pressures. Examination for jugular venous distension at rest or by the abdominojugular test is simple and highly sensitive and specific in assessing left heart pressures in these patients.

Assisted Ventilation Does Not Improve Outcome in a Porcine Model of Single-Rescuer Bystander Cardiopulmonary Resuscitation

BACKGROUND Mouth-to-mouth rescue breathing is a barrier to the performance of bystander cardiopulmonary resuscitation (CPR). We evaluated the need for assisted ventilation during simulated single-rescuer bystander CPR in a swine model of prehospital cardiac arrest. METHODS AND RESULTS Five minutes after ventricular fibrillation, swine were randomly assigned to 8 minutes of hand-bag-valve ventilation with 17% oxygen and 4% carbon dioxide plus chest compressions (CC + V), chest compressions only (CC), or no CPR (control group). Standard advanced life support was then provided. Animals successfully resuscitated received 1 hour of intensive care support and were observed for 24 hours. All 10 CC animals, 9 of the 10 CC + V animals, and 4 of the 6 control animals attained return of spontaneous circulation. Five of the 10 CC animals, 6 of the 10 CC + V animals, and none of the 6 control animals survived for 24 hours (CC versus controls, P = .058; CC + V versus controls, P < .03). All 24-hour survivors were normal or nearly normal neurologically. CONCLUSIONS In this model of prehospital single-rescuer bystander CPR, successful initial resuscitation, 24-hour survival, and neurological outcome were similar after chest compressions only or chest compressions plus assisted ventilation. Both techniques tended to improve outcome compared with no bystander CPR.

Myocardial perfusion pressure: A predictor of 24-hour survival during prolonged cardiac arrest in dogs

Myocardial perfusion pressure, defined as the aortic diastolic pressure minus the right atrial diastolic pressure, correlates with coronary blood flow during cardiopulmonary resuscitation (CPR) and predicts initial resuscitation success. Whether this hemodynamic parameter can predict 24-h survival is not known. We examined the relationship between myocardial perfusion pressure and 24-h survival in 60 dogs that underwent prolonged (20 min) ventricular fibrillation and CPR. Forty-two (70%) animals were initially resuscitated and 20 (33%) survived for 24 h. Myocardial perfusion pressure was significantly greater when measured at 5, 10, 15 and 20 min of ventricular fibrillation in the resuscitated animals than in the non-resuscitated animals (P less than 0.01). Likewise, the myocardial perfusion pressure was also greater in the animals that survived 24 h than in animals that were resuscitated, but died before 24 h (P less than 0.02). Myocardial perfusion pressure measured after 10 min of CPR was 11 +/- 2 mmHg in animals never resuscitated, 20 +/- 3 mmHg in those resuscitated that died before 24 h and 29 +/- 2 mmHg in those that survived 24 h (P less than 0.05). A myocardial perfusion pressure at 10 min of CPR of 20 mmHg or less is an excellent predictor of poor survival (negative predictive value = 96%). Myocardial perfusion pressure is a useful index of CPR effectiveness and therefore may be a useful guide in helping to optimize resuscitation efforts.