© 2003 American Thoracic Society
Cardiopulmonary resuscitation in pulmonary hypertensionTo the Editor:In their excellent study that recently appeared in this journal, Hoeper and colleagues (1) reported data about the outcome after cardiopulmonary resuscitation (CPR) in patients with pulmonary arterial hypertension. Of the 3,130 patients treated within the study period, 513 had cardiopulmonary arrest and CPR was attempted in 132 cases. However, whereas in 66 patients (50%) the initial ECG showed electromechanical dissociation (EMD), asystole, or ventricular fibrillation (VF), in 64 patients (48%) the ECG at the time of CPR showed bradycardia or other unspecified rhythms. Moreover, among the eight long-term survivors listed in Table 3, only three showed an initial ECG clearly compatible with cardiac arrest (asystole or EMD), whereas the ECG of the remaining five patients showed atrioventricular block (#2 and #8), bradycardia (#5 and #6), and sinus rhythm (#7). In two of the patients the reported indication of CPR was a vasovagal syncope, and in one a "respiratory failure caused by an epileptic seizure." We think that a more precise definition of the indications for CPR could be helpful. According to the current international guidelines for CPR and Emergency Cardiovascular Care (2), the ECG rhythms associated with cardiac arrest are VF, pulseless ventricular tachycardia, asystole, and EMD (better defined as pulseless electrical activity), a condition in which electrical activity is organized and no pulse is detectable (2). We have no doubt that all the reported patients with bradycardia, sinus rhythm, or atrioventricular block were pulseless at the time of CPR, but in this case they should have been included in the EMD group, otherwise the reader should assume that patients with atrioventricular block, bradycardia, or even sinus rhythm, but not in cardiac arrest, underwent CPR, and that the occurrence of cardiac arrest in the reported population have been overestimated. The same is true for the vasovagal syncope or the respiratory failure, for which CPR is clearly not the standard treatment. International consensus has developed the Utstein recommendation for reporting cardiac arrest and resuscitation both in intra-hospital (3) and extra-hospital setting (4). We believe that adherence to these recommendations would help to achieve uniform reporting for cardiac arrest events and resuscitation attempts.
Università Cattolica del Sacro Cuore Rome, Italy REFERENCES
From the Authors:We appreciate the comments by Sandroni and colleagues. Current guidelines on studying CPR are based on the most common causes of cardiac arrest. Typical reasons for sudden death in patients with pulmonary arterial hypertension (PAH) may not be adequately represented in these categories. In PAH, profound systemic hypotension may be the harbinger of a catastrophic sequence finally resulting in death. On the other hand, common causes of cardiac arrest in patients with left heart disease, such as ventricular fibrillations, are uncommon in patients with PAH. When writing the article, we chose to give a mere description of the events leading to CPR rather than grouping them into predefined but rather abstract categories. Thereby, readers may be able to get an impression of the situations that potentially result in acute right heart failure in these fragile patients.We disagree with the concept that "... vasovagal syncope or respiratory failure, for which CPR is clearly not the standard treatment." In PAH patients, a simple vasovagal reaction can evolve rapidly in cardiac arrest due to a further reduction of coronary driving pressure (mean arterial pressure minus right atrial pressure) of the hypertrophied and decompensated right heart ventricle. The same applies to respiratory failure and consequent hypoxemia. Therefore, in expert PAH centers, severe vasovagal reactions and respiratory failure are aggressively treated with CPR maneuvers. Clearly, the rate of cardiac arrest was not overestimated given the high proportion of events that were eventually fatal.
a Hannover Medical School Hannover, Germany
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