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Biomedical subjects

D L Hayes

Publications and source records attributed to D L Hayes.

At least 19 recordsLinked to original sources
PubMed1996

Prospective evaluation of a chamomile mouthwash for prevention of 5-FU-induced oral mucositis.

BACKGROUND: Stomatitis has been found to be a major dose-limiting toxicity from bolus 5-fluorouracil-based (5-FU) chemotherapy regimens, despite the use of oral cryotherapy. Pursuant to preliminary data which suggested that a chamomile mouthwash might ameliorate this toxicity, a prospective trial was developed to test chamomile in this situation. METHODS: A Phase III, double-blind, placebo-controlled clinical trial was designed. Patients were entered into the study at the time of their first cycle of 5-FU-based chemotherapy. All patients received oral cryotherapy for 30 minutes with each dose of 5-FU. In addition, each patient was randomized to receive a chamomile or placebo mouthwash thrice daily for 14 days. Stomatitis scores were determined by health care providers and by patients themselves. RESULTS: There were 164 evaluable and well-stratified patients equally randomized to both treatment groups. There was no suggestion of any stomatitis difference between patients randomized to either protocol arm. There was also no suggestion of toxicity. Subset analysis did reveal unsuspected differential effects between males and females that could not be explained by reasons other than chance. CONCLUSION: The resultant data from this clinical trial did not support the prestudy hypothesis that chamomile could decrease 5-FU-induced stomatitis.

Antimetabolites, Antineoplastic↗
PubMed1996

Effect of dual-chamber pacing on systolic and diastolic function in patients with hypertrophic cardiomyopathy. Acute Doppler echocardiographic and catheterization hemodynamic study.

OBJECTIVES: This study sought to evaluate prospectively the acute hemodynamic effect of dual-chamber pacing by using a combined hemodynamic approach of high fidelity pressure and Doppler velocity measurements. BACKGROUND: Dual-chamber pacing has been proposed recently as an alternative in the symptomatic treatment of patients with hypertrophic obstructive cardiomyopathy. Although early reports documented a decrease in left ventricular outflow tract gradient and symptomatic improvement, questions remain about the hemodynamic effects of dual-chamber pacing on systolic and diastolic function. METHODS: Twenty-nine patients with hypertrophic cardiomyopathy underwent a combined cardiac catheterization and Doppler echocardiographic study during normal sinus rhythm and P-synchronous pacing at various atrioventricular (AV) intervals. High fidelity pressure measurements of left ventricular inflow and left atrial pressures, ascending aortic pressure, thermodilution cardiac output and Doppler mitral flow velocity curves were obtained to evaluate both systolic and diastolic left ventricular function. RESULTS: During AV pacing at the shortest delay of 60 ms, there was a significant decrease in cardiac output (p < 0.05) and peak positive dP/dt (p < 0.05), an increase in mean left atrial pressure (p < 0.05) and a prolongation of tau, the time constant of relaxation (p < 0.05), compared with that during normal sinus rhythm. During pacing at the optimal AV delay (longest AV interval with pre-excitation), there was a similar trend, with deterioration in both systolic and diastolic function variables but of lesser magnitude than that during pacing at the shortest AV intervals. The deterioration in both systolic and diastolic function was present in 21 patients with and 8 without left ventricular outflow obstruction. There was a modest decrease in left ventricular outflow tract gradient from 73.3 +/- 45.0 (mean +/- SD) to 61.3 +/- 40.5 mm Hg (p = 0.03) during dual-chamber pacing at the optimal AV delay compared with that during normal sinus rhythm. CONCLUSIONS: The acute effect of pacing the right atrium and ventricle may be detrimental to both systolic and diastolic function of the left ventricle, particularly at the short AV intervals. Further studies of the long-term effects of dual-chamber pacing in carefully performed randomized studies are needed.

Blood Flow Velocity↗
PubMed1996

Extraction of the Telectronics Accufix 330-801 atrial lead: the Mayo Clinic experience.

OBJECTIVE: To document a cumulative experience with removal of the Telectronics 330-801 Accufix atrial lead after it was withdrawn from the market. DESIGN: We reviewed our results with 96 attempted lead extraction procedures through Dec. 1, 1995. MATERIAL AND METHODS: All patients underwent preoperative assessment, including fluoroscopic screening of the lead. Patients had blood typing and screening done before the extraction procedure, and extractions were performed with cardiac surgical intervention available. Pacing dependence was assessed to determine the need for temporary pacing. RESULTS: The mean patient age was 65.7 +/- 1.6 years and the mean duration of lead implantation was 31.0 +/- 1.4 months. Of the 96 lead extractions attempted, 94 were successful. Of the 96 cases, the retention wires were normal in 29, fractured without protrusion in 34, and fractured with protrusion in 33. Fifty-three leads were removed with use of simple traction only, and seven leads were removed by using a locking stylet and telescoping sheaths. The Cook workstation was used in the removal of 32 leads through the femoral vein; in 1 of these 32 patients, the retention wire was removed before lead extraction. The retention wire was removed but the lead was left intact in one patient. One lead was removed during an opertive maze procedure. Associated complications were minimal. CONCLUSION: Although lead extraction is a potentially fatal procedure, the Telectronics 330-801 Accufix atrial lead can be extracted safely with minimal morbidity when performed by experienced personnel.

Aged↗
PubMed1995

Expanding indications for permanent pacemakers.

PURPOSE: To review the current clinical experience with new and expanding indications for permanent cardiac pacing. DATA SOURCES: A MEDLINE search was done of the English-language literature published from 1980 through 1994 about indications for permanent pacing. Five major areas were identified and searched: cardiomyopathies, atrial fibrillation, the long QT syndrome, cardiac transplantation, and vasovagal syncope. A manual search was then done for other contributions, including abstracts. STUDY SELECTION: Because published reports in these areas are scarce, all of the peer-reviewed articles and most of the relevant abstracts found were reviewed. DATA EXTRACTION: Data were manually extracted from the various sources, and the reports were classified and summarized according to specific indications. RESULTS: Pacing is becoming an important option in the treatment of patients with symptomatic drug-resistant hypertrophic obstructive cardiomyopathy. Symptomatic and hemodynamic benefits have been shown in patients with pacing over various periods of follow-up. In patients with the long QT syndrome in whom medical therapy had failed, pacing at relatively fast rates markedly reduced symptoms and almost completely abolished fainting spells. Preliminary results suggest that pacing may be beneficial in dilated cardiomyopathy and in preventing episodes of paroxysmal atrial fibrillation. Further studies are needed to clarify the mechanisms of and to improve selection criteria for pacing in these conditions. Our ability to select cardiac transplant recipients for permanent pacing and our ability to optimize the timing of pacing in these patients have recently improved considerably. The role of pacing therapy in patients with neurally mediated (vasovagal) syncope remains incompletely understood. Better classification of these patients, made according to the sequence of hemodynamic events leading to syncope, is likely to clarify the potential benefit of pacing in these patients and improve the selection of patients for pacing. CONCLUSION: Few peer-reviewed clinical trials have been done, and further studies are needed to confirm the promising effects of pacing in patients with these newly recognized and expanding indications for pacing.

Atrial Fibrillation↗
PubMed1995

Mechanism of hemodynamic improvement by dual-chamber pacing for severe left ventricular dysfunction: an acute Doppler and catheterization hemodynamic study.

OBJECTIVES: This study was undertaken to determine the mechanism by which improvement in hemodynamic variables may occur with dual-chamber pacing in patients with severe left ventricular dysfunction. BACKGROUND: Dual-chamber pacing has recently been proposed as a therapeutic alternative for the relief of symptoms in patients with dilated cardiomyopathy. METHODS: Fifteen patients with severe left ventricular systolic dysfunction were studied acutely during atrioventricular (AV) sequential pacing at various AV intervals (60, 100, 120, 140, 180 and 240 ms) with use of combined Doppler velocity curves and pressures obtained by high fidelity manometer-tipped catheters and thermodilution cardiac output. RESULTS: Neither cardiac output nor mean left atrial pressure was significantly different when hemodynamic variables in the baseline state were compared with those during AV sequential pacing at the various AV intervals in all patients. The patients were classified into two groups. In group I (eight patients with PR intervals > 200 ms on the rest 12-lead electrocardiogram), cardiac output was significantly increased when AV sequential pacing at the optimal AV interval to output was compared with that at the baseline state (3.0 +/- 1.0 vs. 3.9 +/- 0.43 liters/min, p = 0.005) because timing of mechanical atrial and ventricular synchrony was optimized. In addition, left ventricular end-diastolic pressure and duration of diastolic filling were increased, and diastolic mitral regurgitation was abolished. In group II (seven patients who had normal AV conduction at rest), cardiac output during AV pacing decreased from the baseline value without change in the diastolic filling period. CONCLUSIONS: Dual-chamber pacing may improve acute hemodynamic variables in selected patients with dilated cardiomyopathy, mainly by optimization of the timing of mechanical atrial and ventricular synchrony. Reestablishment of the optimal diastolic filling period and abolition of diastolic mitral regurgitation may also contribute to hemodynamic improvement.

Aged↗
PubMed1995

Atrial "J" pacing lead retention wire fracture: radiographic assessment, incidence of fracture, and clinical management.

UNLABELLED: In November 1994, Telectronics Pacing Systems issued a voluntary recall of their Accufix 330-801 and 329-701 "J"-shaped atrial pacemaker leads. To assess the integrity of the lead, 156 consecutive patients with the Accufix 330-801 atrial lead implanted underwent fluoroscopic screening. Leads were visualized in at least two orthogonal views. When identified, fractured retention wires were classified into one of four groups, depending on the degree of wire extrusion outside of the lead insulation. RESULTS: Of the 156 patients, 35 patients (22.4%) had a definite retention wire fracture, and an additional 13 patients (8.3%) had indeterminate leads. Neither the age of the patients, the time since lead implant, nor the site of fracture correlated with the incidence of wire fracture. When analyzed to include indeterminate leads that were re-evaluated and found to be fractured, as well as two leads that were identified as being radiographically normal but found to be fractured after extraction, the incidence of retention wire fracture is 25.6% (40 of 156 leads evaluated). CONCLUSIONS: The incidence of retention wire fracture in the Accufix 330-801 lead is significantly higher than originally reported. Patients should be notified of the potential dangers associated with this lead. Cardiac digital fluoroscopy is an effective method of screening for wire fracture. Leads with fractured retention wires should be extracted and those with normal fluoroscopic appearance should undergo regular fluoroscopic screening.

Aged↗
PubMed1995

Multicenter experience with a bipolar tined polyurethane ventricular lead.

A multicenter study was undertaken to determine the failure rate of a specific bipolar tined polyurethane ventricular pacing lead, the Medtronic 4004/4004M pacing lead. Seven centers in the United States and Canada implanted 586 Medtronic 4004/4004M pacing leads. The study was designed to determine the probability and clinical manifestations of lead failure. Only failures compatible with an insulation problem were included. The Kaplan-Meier estimate of the percentage of 4004/4004M lead failures within 4 years after implantation was 14.1% (95% confidence interval: 8.5%-19.3%). Failures were manifested as sensing abnormalities, failure to capture, early battery depletion, and significant decrease in measured impedance compared with previous impedance measurements. The observed rate of failure is unacceptable, and strong consideration should be given to replacing the 4004/4004M pacing lead in pacemaker dependent patients and closely monitoring nondependent patients.

Adolescent↗
PubMed1995

Snare removal of a telectronics accufix atrial J retention wire.

A voluntary recall of the Telectronics Accufix models 330-801 and 329-701 "J"-shaped atrial pacemaker leads has been issued because of fracture and extrusion of the J-shaped retention wire. Such extrusion can result in laceration of the atrium or surrounding vascular structures. Herein we describe a patient with a fractured and extruded retention wire that was snared and removed percutaneously; the atrial lead was left intact, and pacing function was satisfactory. This unique procedure can be used to avoid the morbidity associated with percutaneous lead extraction or thoracotomy and to prevent potential dislodgment and embolization of the retention wire during lead extraction.

Child↗
PubMed1994

Long-term survival after permanent pacemaker implantation for sick sinus syndrome.

In this population-based study, long-term survival and prognostic factors were examined in 148 patients, 55 men and 93 women, from Olmsted County, Minnesota, who had permanent pacemaker implantation for sick sinus syndrome between 1969 and 1991. The overall survival for patients who had received a permanent pacemaker for sick sinus syndrome was significantly worse than that of an age- and sex-matched control population (p < 0.0001). The increased mortality was attributable at least in part to the presence of structural heart disease in patients with sick sinus syndrome who had undergone permanent pacemaker implantation (82 of 148 patients, 55%). Survival of patients with isolated sick sinus syndrome was comparable (p = 0.6729), whereas in patients with structural heart disease it was significantly worse than expected (p < 0.0001). Symptoms were eliminated or improved in 116 patients (78%) after pacemaker implantation. Multivariate analysis identified congestive heart failure, valvular heart disease, history of stroke or transient ischemic attack, and age as independent risk factors for mortality. However, there was a trend toward decreased survival in patients who had received ventricular pacing compared with those who had received dual-chamber pacing, but this difference did not reach statistical significance (p = 0.0556). The mode of pacing was not an independent risk factor (p = 0.23). The observed survival of patients aged < 80 years was significantly worse than expected (p < 0.0001), whereas that of patients aged > or = 80 years was similar to the expected (p = 0.22).

Adult↗
PubMed1994

Long-term survival after pacemaker implantation for heart block in patients > or = 65 years.

Permanent pacing can prevent recurrent symptoms and reduce mortality in elderly patients with symptomatic high-degree atrioventricular (AV) block. However, long-term survival with respect to comparable control subjects has not been well defined. In our study, relative long-term survival and prognostic predictors after permanent pacemaker implantation for symptomatic high-degree AV block were assessed among all residents of Olmsted County, Minnesota, who were > or = 65 years old. Of the 154 patients, 77 were men and 77 were women (mean age 80 +/- 7 years). Follow-up was 0.1 to 19.8 years (mean 4.2 +/- 2.8). Sixty-nine patients had isolated AV block and 85 had coexisting heart disease. Observed survival at 1, 3, 5, and 10 years was 85%, 68%, 52%, 21%, and 72%, 50%, 31%, 11% for patients with isolated AV block and patients with coexisting heart disease, respectively (p = 0.006). Observed survival in patients 65 to 79 years old with isolated AV block was comparable to age- and sex-matched cohorts (p = 0.53), but in patients aged > or = 80 years, it was less than that for control subjects (p = 0.014). In patients with coexisting heart disease, observed survival was less than that for control subjects in patients 65 to 79 years old (p < 0.001) and > or = 80 years (p < 0.001). Multivariate analysis identified congestive heart failure, chronic obstructive pulmonary disease, age, syncope, insulin-dependent diabetes mellitus, and male gender as independent predictors of increased mortality.

Age Factors↗
PubMed1994

Consistent subcutaneous prepectoral implantation of a new implantable cardioverter defibrillator.

OBJECTIVE: To describe the use of a new implantable cardioverter defibrillator (ICD) that can be placed in the prepectoral region rather than implanted in the abdominal wall. DESIGN: We report the experience of placement of this new ICD in the prepectoral region in 13 patients from Sept. 28, 1993, through Jan. 10, 1994, at the Mayo Clinic. MATERIAL AND METHODS: Thirteen consecutive patients offered this new ICD underwent placement of transvenous defibrillation leads, and the pulse generator was placed in a pocket formed in the subcutaneous, prepectoral space. Testing ensured a defibrillation threshold of 24 J or less. RESULTS: In all 13 patients, the pulse generator could be placed in the subcutaneous, prepectoral space. In all except one patient, acceptable defibrillation thresholds were achieved by using lead systems placed totally transvenously. Only one patient required placement of a subcutaneous patch. All but two patients were dismissed from the hospital within 3 days after the ICD implantation. CONCLUSION: Consistent subcutaneous, prepectoral placement of this new ICD pulse generator is possible. Because the entire procedure can be performed in the pacemaker implantation room, the potential exists for decreasing the duration of the hospitalization and associated costs.

Aged↗
PubMed1994

Recent advances in cardiac pacing.

This article reviews recent studies, chapters, and review articles describing advances in cardiac pacing. Initially we discuss expanding and controversial pacing indications, including neurocardiogenic syncope and hypertrophic as well as dilated cardiomyopathies. Recent contributions to the understanding of factors influencing pacing mode selection are then discussed, including survival and atrial fibrillation in the various modes, the hemodynamic importance of atrioventricular synchrony and adaptive atrioventricular intervals, the importance of rate adaptation, the development of pacemaker syndrome, pacemaker response to the development of atrial arrhythmias, and special pacing modes such as VDD and AAIR. Finally, recent advances in rate-adaptive sensors and algorithms are reviewed, including preliminary results with dual sensors.

Bradycardia↗
PubMed1994

Report of the NASPE Policy Conference training requirements for permanent pacemaker selection, implantation, and follow-up. North American Society of Pacing and Electrophysiology.

NASPE proposes and supports the concept of a two-tracked training system in cardiac pacing. Track I training will properly train physicians for the prescription of pacemakers and the monitoring of pacemaker patients, and track II training will properly prepare physicians for the implantation of pacemakers. Regardless of specialty (cardiologist or surgeon) or training venue (cardiac pacing fellowship, cardiac electrophysiology and pacing fellowship, sabbatical or mentor sponsored training), it is recommended that these minimum standards be required for hospital credentialing. NASPE also supports the voluntary institution by training program directors of core pacing training in cardiovascular disease and cardiac electrophysiology fellowships. This core training does not in itself constitute proper track I or II training for physicians interested in adequately prescribing, monitoring, or implanting cardiac pacemakers.

Cardiac Pacing, Artificial↗
PubMed1994

Clinical surveillance of an active fixation, bipolar, polyurethane insulated pacing lead, Part II: The ventricular lead.

Since 1989, 72 Telectronics 330-201 active fixation, polyurethane insulated ventricular leads (Accufix) have been implanted at the Mayo Clinic. There were four (5.6%) acute lead related complications (perforation, microdislodgment, and macrodislodgment), three of which led to early reoperation. Over a follow-up time of up to 2.7 years (median 9.4 months), there were six (8.3%) chronic lead related complications but no failures of lead material. Most of these complications developed during the first month, and half of them were transient, with documented improvement later. Two patients (2.8%) required reoperation for chronic complications. At follow-up examination of the pacing thresholds, usually performed about 3 months after implantation, 14.3% of the examined patients had high pacing thresholds necessitating high-output programming. The mechanisms and later evolution of this phenomenon should be further evaluated.

Adult↗