Irrigated Radiofrequency Catheter Ablation Guided by Electroanatomic Mapping for Recurrent Ventricular Tachycardia After Myocardial Infarction

Background— Recurrent ventricular tachycardia (VT) is an important cause of mortality and morbidity late after myocardial infarction. With frequent use of implantable cardioverter-defibrillators, these VTs are often poorly defined and not tolerated for mapping, factors previously viewed as relative contraindications to ablation. This observational multicenter study assessed the outcome of VT ablation with a saline-irrigated catheter combined with an electroanatomic mapping system.

Methods and Results— Two hundred thirty-one patients (median LV ejection fraction, 0.25; heart failure in 62%) with recurrent episodes of monomorphic VT (median, 11 in the preceding 6 months) caused by prior myocardial infarction were enrolled. All inducible monomorphic VTs with a rate approximating or slower than any spontaneous VTs were targeted for ablation guided by electroanatomic mapping during sinus rhythm and/or VT. Patients were not excluded for multiple VTs (median, 3 per patient) or unmappable VT (present in 69% of patients). Ablation abolished all inducible VTs in 49% of patients. The primary end point of freedom from recurrent incessant VT or intermittent VT after 6 months of follow-up was achieved for 123 patients (53%). In 142 patients with implantable cardioverter-defibrillators before and after ablation for intermittent VT who survived 6 months, VT episodes were reduced from a median of 11.5 to 0 ( P <0.0001). The 1-year mortality rate was 18%, with 72.5% of deaths attributed to ventricular arrhythmias or heart failure. The procedure mortality rate was 3%, with no strokes.

Conclusions— Catheter ablation is a reasonable option to reduce episodes of recurrent VT in patients with prior myocardial infarction, even when multiple and/or unmappable VTs are present. This population remains at high risk for death, warranting surveillance and further study.

A case of peroneal neuropathy-induced footdrop. Correlated and compensatory lower-extremity function

This article reports on the case of a man with peroneal neuropathy-induced footdrop who was seen at the authors' institution 3 years after open reduction and internal fixation of a proximal fibular fracture and a distal, spiral, oblique tibial fracture of the right leg. A comprehensive gait analysis was conducted. A significant footdrop in gait resulted in a "reverse check mark" center-of-pressure pattern, an increased transverse-plane rotation of the foot, and excessive knee and hip flexion in the sagittal plane. These objective findings documented significant dysfunction within the involved lower extremity; in addition, aberrant biomechanics were observed in structures other than the site of initial injury within both limbs.

Effects of occupational medical surveillance programs as perceived by respondents to the Occupational Safety and Health Administration's 1990-1991 survey

Among all establishments perceiving a change as a result of their medical surveillance program, 43% of those employing 250 or more employees did so; for the smallest establishments, this figure drops to 7%. The changes most often perceived, regardless of size class of establishment or industry division, were in employee relations, injury rates, and insurance costs. Establishments with the most comprehensive risk reduction strategies were most likely to attribute benefits to their medical surveillance programs. Benefits of medical surveillance perceived by the Phase II respondents include reduced costs, early detection of medical problems, increased productivity, and a reduced injury or illness rate. Most firms have no systematic method or procedures for evaluating the effectiveness of their medical surveillance programs.

The Occupational Safety and Health Administration's 1990-1991 survey of occupational medical surveillance prevalence and type of current practices

For all industry divisions, the likelihood that an establishment will have a medical surveillance program increases directly with size of establishment. Among establishments with 1 to 19 employees, only 4% have medical surveillance programs whereas 56% of establishments that employed 250 or more employees had such programs. The most common time to administer medical surveillance is preemployment. The second most common time to conduct medical surveillance is at periodic intervals. The most common component of medical surveillance programs is a general physical examination. This component of medical surveillance is also the most common element of preemployment surveillance, preplacement surveillance, periodic surveillance, preexit examinations, and surveillance for respirator users. Among the group of Phase II establishments, audiometric testing was the most common periodic test identified. Musculoskeletal testing is performed by 45% of firms administering preplacement examinations and by 38% of firms with preemployment examinations. Across all industry divisions, 14% of establishments that have a medical surveillance program also perform biologic monitoring of some employees.

The purposes of occupational medical surveillance in US industry and related health findings

The primary purpose for implementing medical surveillance is to protect the general health and fitness of all employees. The next most frequent purpose of medical surveillance programs is to determine whether employees have the physical capability to perform their jobs (ie, surveillance to establish "fitness for duty"). The most commonly reported uses of medical surveillance data for establishments across all industry divisions were to implement or change work practices, to implement or change administrative control programs, to modify training programs, and to change personal protective equipment. Eighteen percent of establishments in all size classes and industries that have medical surveillance programs have identified adverse health effects among employees. The health effects most commonly identified by the medical surveillance programs were repetitive trauma, hearing loss, and skin disorders. Programs designed to detect hearing loss and cumulative trauma disorders, are in fact, finding these adverse effects. Among employees actually receiving periodic medical surveillance tests (6 million), 5% were found to have an abnormal test result.