The Natural History of Recovery Following Sudden Cardiac Arrest and Internal Cardioverter-Defibrillator Implantation

Abstract and Introduction

Abstract

The purposes of this review are to 1) summarize current knowledge regarding the "natural history of recovery" (physical functioning, psychological adjustment, and neurologic impairments) following sudden cardiac arrest and internal cardioverter-defibrillator implantation over the first year; and 2) discuss the implications for the development of nursing intervention programs based on the natu-ral history of recovery. The natural history serves as a basis for understanding the recovery experiences of sudden cardiac arrest survivors as well as determining how intervention programs might help the most.

Introduction

Sudden cardiac arrest (SCA) claims approximately 250,000 lives in the United States per year, representing 40% of the total deaths resulting from cardiovascular disease.^[1] SCA is defined as "death caused by underlying heart disease occurring without symptoms or with symptoms of less than 1 hour's duration."^[2] An individual, often in good health, collapses with no warning when the effective pumping action of the heart ceases. Consciousness is lost within a matter of seconds. There may be associated seizure activity, gasping respirations, and urine incontinence as the brain becomes deprived of oxygen. If circulation is not restored or external chest compressions and ventilations applied within 4 minutes, there will be permanent neurologic damage, and in approximately 8-10 minutes the individual will be dead.^[3] Although there are many causes of SCA, autopsy studies indicate that 75% of victims have significant atherosclerotic heart disease, usually involving two or three coronary arteries.^[4] Seventy-eight percent of successfully resuscitated victims of SCA have been shown to have a history of remote heart attack, chest pain, congestive heart failure, or high blood pressure, with the presenting rhythm at the time of resuscitation being ventricular fibrillation. Clinical studies have shown that patients with ventricular electrical instability (e.g., frequent premature beats, multiformed ventricular beats), extensive coronary artery narrowing, and abnormal left ventricular function are at higher risk for developing SCA.^[5] Approximately 29% of persons now survive the initial cardiac arrest, with a large number undergoing automatic defibrillator implantation.^[3] Advances in diagnostic and therapeutic options have increased survival rates for patients following SCA and those with ventricular arrhythmias, particularly with regard to improvements in resuscitation, pharmacologic therapy, and the development of internal cardioverter-defibrillators (ICDs).

ICDs were first developed in the 1980s and approved for implantation in the United States in 1985.^[6] Since 1985, approximately 100,000 individuals have received an ICD, with 20,000-40,000 new implants annually. The first devices were large, required a large chest incision, delivered only high-energy shocks, and could not be programmed. By the early 1990s, ICDs were designed with antitachycardia and bradycardia functions, could deliver low- level cardioversion shocks, and were implanted using transvenous leads without surgery. Since 1995, ICDs have been implanted pectorally using one or two transvenous leads similar to that of a pacemaker; they are much smaller in size (2.532.5 in) and weight (<1 lb) and are fully programmable. The majority of individuals who have received the ICD are men over 60 years old, but the ICD has been used in infants and older adults. Research investigations have already demonstrated that ICDs do prolong life when compared with antiarrhythmic drugs.^[7] The questions that still need to be answered relate to quality of life following ICD implantation and the cost effectiveness of various therapies designed to promote adaptation following ICD implantation.^[8]

To design effective intervention programs to enhance recovery for SCA survivors who receive an ICD, the process of recovery from the viewpoint of the patient must first be outlined and understood. Past research investigations targeting recovery following SCA and ICD implantation have been hampered by small sample size and cross-sectional study designs. Moreover, they have not described adjustment over a long enough period to ascertain the "natural history" of recovery, rarely include families and significant others, and often do not report neurologic deficits associated with resuscitation. This article 1) summarizes current knowledge regarding the "natural history of recovery" (i.e., physical functioning, psychological adjustment, and neurologic impairments) following SCA and ICD implantation over the first year; and 2) discusses the implications for the development of nursing intervention programs based on the natural history of recovery.

Despite limited longitudinal studies outlining the experiences of individuals recovering from SCA, a synthesis of past research suggests that the event^[9] is followed by a period of intense adjustment during which new coping skills are learned and lifestyle changes are incorporated. This period of adjustment varies from individual to individual but generally lasts from hospital discharge to 6-12 months.^[10,11] Research investigations have not addressed adjustment after a 12-month period, but reports have demonstrated that most individuals have returned to "normal" function by 12 months. Adaptive tasks for SCA survivors during the intense adjustment period include denying or minimizing the seriousness of the disease, seeking relevant information, requesting emotional support, learning specific illness-related behaviors, returning to work, becoming physically active, setting goals, rehearsing alternative outcomes, and discovering patterns of meaning.^[9,12] If the patient is able to do this alone and coping skills are acquired without difficulty, then normal activities and a normal lifestyle an be predicted. Without help and guidance from health care providers, very few, if any, individuals can be expected to return to pre-SCA levels of functioning. Individuals recovering from SCA and ICD implantation expect help and support from their health care providers during the intense recovery period of the first year.

Prog Cardiovasc Nurs. 2001;16(4) © 2001 

Cite this: The Natural History of Recovery Following Sudden Cardiac Arrest and Internal Cardioverter-Defibrillator Implantation - Medscape - Oct 01, 2001.