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Biomedical subjects

R D Fletcher

Publications and source records attributed to R D Fletcher.

At least 37 records · Page 2Linked to original sources
PubMed1993

Veterans Affairs congestive heart failure antiarrhythmic trial. CHF STAT Investigators.

This is a prospective, double-blind, placebo-controlled trial to determine the effect of antiarrhythmic drug therapy on mortality in patients with congestive heart failure and ventricular arrhythmia. Patients will be assigned to receive either amiodarone or placebo. Eligible patients include those with ischemic and nonischemic congestive heart failure and with > or = 10 ventricular premature beats per hour. All patients must have shortness of breath with minimal exertion or paroxysmal nocturnal dyspnea, a left ventricular internal dimension (LVIDd) by echocardiogram of > or = 55 mm or a cardiothoracic ratio of > 0.5 and an ejection fraction of < or = 40%. All patients will receive vasodilator therapy, unless they find it intolerable. Patients will be entered into the study for 2.5 years and followed for an additional 2 years. Drug therapy will be continued for all patients throughout the entire study unless adverse reactions occur that necessitate individualized treatment. The expectation is that 674 patients will be entered into the study from 25 participating centers. This sample size will allow for the detection of a 33% decrease in 2-year mortality (20% vs 30%) in the treated patients compared with those in the placebo group, with a power of 0.90 and a 2-sided alpha level of 0.05. Intermittent Holter monitoring, radionuclide ventriculograms, pulmonary function tests, echocardiograms, and blood tests, including arterial blood gases, will be required for each patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Amiodarone↗
PubMed1993

Radiofrequency catheter ablation of ectopic atrial tachycardia using paced activation sequence mapping.

OBJECTIVES: Although ectopic atrial tachycardia is infrequent, it can be an important clinical challenge. We sought to define an alternative therapeutic approach to this refractory problem. BACKGROUND: Radiofrequency energy catheter ablation has been used to treat a variety of ventricular and supraventricular arrhythmias but has not been proved efficacious in the management of ectopic atrial tachycardia. METHODS: Ten patients (14 to 47 years of age) referred with refractory ectopic atrial tachycardia were studied. Mapping techniques included identification of earliest atrial activation, confirmation of concordance of P wave configuration during spontaneous tachycardia and pacing from the ablation catheter, and paced activation sequence mapping. The paced activation sequence mapping compared the activation sequence at multiple atrial sites during spontaneous tachycardia with that recorded during pacing from the ablation catheter. The catheter was steered to a point where pacing reproduced the spontaneous activation sequence. RESULTS: Foci were right atrial in eight patients and left atrial in two. In 8 of 10 patients, 514 +/- 97 (SE) J and 5.7 +/- 2.3 (SD) J radiofrequency energy applications ablated the ectopic focus. Seven of these eight patients presented with one focus and one had two discrete and stable foci. Ablation was unsuccessful in two patients with multiple foci. No complications occurred. An arrhythmia focus recurred in two patients and one patient underwent successful repeat ablation. The other patient was managed medically. All seven patients with successful ablation are symptom free after 6.5 +/- 3.8 months. CONCLUSIONS: Our preliminary experience suggests that with the use of both paced activation sequence mapping and standard techniques, radiofrequency ablation of ectopic atrial tachycardia may be a safe and effective form of therapy.

Adolescent↗
PubMed1993

Effect on coronary artery anatomy of radiofrequency catheter ablation of atrial insertion sites of accessory pathways.

OBJECTIVES: The purpose of this study was to analyze the effects of radiofrequency catheter ablation of the atrial insertion site of accessory pathways on the angiographic appearance of coronary arteries. BACKGROUND: Radiofrequency catheter ablation of accessory pathways requires the application of energy to the endocardial surface of the atrioventricular groove adjacent to the major epicardial coronary arteries. A systematic analysis of the effect of radiofrequency ablation on coronary arteries has not previously been demonstrated. METHODS: Seventy consecutive patients with 76 accessory pathways (7 right free wall, 44 left free wall, 12 posteroseptal, 8 anteroseptal and 5 midseptal) were studied. Quantitative coronary angiography was performed before, immediately after and a mean of 69 +/- 42 days after radiofrequency catheter ablation. RESULTS: Coronary artery diameter adjacent to the ablating electrode was 2.6 +/- 0.9 mm before ablation, 2.7 +/- 0.9 mm immediately after ablation and 2.7 +/- 1.0 mm at the time of follow-up study. Angiographic findings were unchanged from baseline in 69 of 70 patients immediately after ablation and in all 70 patients at the time of follow-up study. CONCLUSIONS: Radiofrequency catheter ablation of the atrial insertion site of accessory pathways does not result in short-term angiographic changes in coronary artery anatomy.

Adolescent↗
PubMed1993

North American Society of Pacing and Electrophysiology policy statement. The NASPE/BPEG defibrillator code.

A new generic code, patterned after and compatible with the NASPE/BPEG Generic Pacemaker Code (NBG Code) was adopted by the NASPE Board of Trustees on January 23, 1993. It was developed by the NASPE Mode Code Committee, including members of the North American Society of Pacing and Electrophysiology (NASPE) and the British Pacing and Electrophysiology Group (BPEG). It is abbreviated as the NBD (for NASPE/BPEG Defibrillator) Code. It is intended for describing the capabilities and operation of implanted cardioverter defibrillators (ICDs) in conversation, record keeping, and device labeling, and incorporates four positions designating: (1) shock location; (2) antitachycardia pacing location; (3) means of tachycardia detection; and (4) antibradycardia pacing location. An additional Short Form, intended only for use in conversation, was defined as a concise means of distinguishing devices capable of shock alone, shock plus antibradycardia pacing, and shock plus antitachycardia and antibradycardia pacing.

Defibrillators, Implantable↗
PubMed1993

Radiofrequency endocardial catheter ablation of accessory atrioventricular pathway atrial insertion sites.

BACKGROUND: High rates of success using radiofrequency ablation energy have rapidly transformed catheter ablation from an investigational procedure to the nonpharmacological therapy of choice for symptomatic Wolff-Parkinson-White syndrome. Prior studies of radiofrequency accessory pathway ablation were based on a ventricular approach. Risks associated with prolonged arterial catheter manipulation, retrograde left ventricular catheterization, and production of ventricular lesions required for successful ventricular insertion ablation can be avoided using atrial insertion ablation procedures. The purpose of the present study was to define the safety and efficacy of accessory pathway ablation using radiofrequency energy delivered solely to accessory atrioventricular pathway atrial insertion sites. METHODS AND RESULTS: One hundred fourteen patients with accessory pathway-mediated tachycardia underwent attempted radiofrequency current ablation at the accessory pathway atrial insertion site. All catheters were introduced transvenously. Left-sided accessory pathways were approached using transseptal left atrial catheterization techniques. Retrograde localization of the atrial insertion site during reentrant tachycardia was characterized by 40 +/- 15-msec local ventriculoatrial and 79 +/- 17-msec surface QRS to local atrial electrogram intervals. Presumed accessory pathway potentials were present in only 30% of ablation site electrograms. Successful ablation required 6.2 +/- 5.3 radiofrequency energy applications. Cumulative energy dose required for success was 2,341 +/- 2,233 J. There were no complications associated with transseptal catheterization. Energy delivery to accessory pathway atrial insertion sites was associated with non-life-threatening complications in two patients. Recurrent conduction requiring repeat ablation occurred in 10 of 115 (9%) successfully ablated accessory pathways, all within 1 month of the ablation procedure. After 21.2 +/- 4.6 months of follow-up, 108 of 114 (95%) patients are asymptomatic and without evidence of accessory pathway conduction. CONCLUSIONS: The atrial insertion approach to accessory pathway ablation is safe and highly effective. This approach compares favorably with the retrograde ventricular insertion ablation technique. Atrial insertion ablation eliminates the need to produce ventricular lesions and avoids the risks of prolonged arterial catheter manipulation and retrograde left ventricular catheterization.

Adult↗
PubMed1993

Characterization of ventricular fibrillation based on monophasic action potential morphology in the human heart.

BACKGROUND: Recent studies examining mechanisms of defibrillation have focused on prolongation of graded cellular response duration during refractory period stimulation. This mechanism assumes that defibrillation shocks interact with ventricular cells during the process of repolarization. METHODS AND RESULTS: To test this assumption, we examined monophasic action potentials (MAPs) from 171 episodes of induced ventricular dysrhythmia associated with loss of systemic perfusion pressure in 22 patients undergoing nonthoracotomy defibrillator implantation. Ventricular fibrillation (VF)/polymorphic ventricular tachycardia (PVT), defined by an irregular limb lead I morphology, was present in 156 dysrhythmia episodes. Monomorphic ventricular tachycardia (VT), present in the remaining 15 episodes, was associated with regular limb lead morphology. All episodes were examined for MAP cycle length, variation, fractionation, and repolarization. VF/PVT cycle length was 215 +/- 28 msec, with a 14 +/- 7% (33 +/- 20-msec) cycle length variability. Nonfractionated MAP recordings were found in 122 of 156 VF/PVT episodes. Episodes characterized as VF by ECG criteria (n = 136) showed lack of MAP diastole and had a mean cycle length of 213 +/- 27 msec. Episodes characterized as PVT (n = 20) were associated with amiodarone therapy and had occasional MAP diastole and a significantly longer mean cycle length of 257 +/- 22 msec (p < 0.001). Monomorphic VT had a mean cycle length of 261 +/- 29 msec, minimal cycle length variation (1 +/- 3%), absence of MAP fractionation, and consistent degree of repolarization before restimulation. CONCLUSIONS: These results suggest that human VF cycle length is limited by cellular refractory periods so that defibrillating shocks interact with cells primarily during their refractory period.

Action Potentials↗
PubMed1993

Optimization of biphasic waveforms for human nonthoracotomy defibrillation.

BACKGROUND: Biphasic waveforms reduce defibrillation threshold (DFT) in a wide variety of models. Although there are several human studies of long-duration, high-tilt biphasic waveform defibrillation, the specific biphasic waveform shape required to achieve optimal DFT reduction is unknown. METHODS AND RESULTS: This study tested the effect of single capacitor biphasic waveform tilt modification on DFT using a paired study design in 18 patients undergoing nonthoracotomy defibrillator implantation. Baseline DFT was obtained using a 65% tilt, simultaneous pulse, bidirectional monophasic shock from a right ventricular cathode to a coronary sinus or superior vena cava lead and a subscapular patch. The single-capacitor biphasic waveform shocks, delivered over the same pathways, consisted of either both phases at 65% tilt (65/65 biphasic waveform) to produce an overall tilt of 88% and a delivered energy 11% greater than monophasic shock or both phases at 42% tilt (42/42 biphasic waveform) to produce an overall tilt of 66% and delivered energy equal to monophasic shock. The 65/65 biphasic waveform reduced stored energy DFT 25%, from 16.2 +/- 4.4 J with monophasic shock to 12.1 +/- 5.3 J (P < .02); however, it did not significantly reduce the delivered energy DFT. In contrast, the 42/42 biphasic waveform required 49% less stored energy (16.2 +/- 4.4 J, monophasic shock, vs 8.3 +/- 3.3 J, biphasic waveform; P < .001) and 49% less delivered energy (14.2 +/- 3.8 J, monophasic shock, vs 7.3 +/- 2.9 J, biphasic waveform; P < .001) than monophasic shock for successful defibrillation. The 42/42 biphasic waveform delivered energy DFT was 4.6 +/- 5.2 J (39%) less than 65/65 biphasic waveform DFT (P < .002). CONCLUSIONS: DFT reduction is an inherent electrophysiological property of biphasic waveforms that is independent of delivered energy. Overall biphasic waveform tilt and the relative amplitudes of the waveform phases are important factors in defibrillation efficacy. Defibrillation with a 42/42 biphasic waveform is more efficacious than 65/65 biphasic waveform defibrillation; however, the optimal biphasic waveform remains unknown.

Adult↗
PubMed1993

Graphical electrocardiogram waveforms as part of an integrated hospital system's patient record.

The U.S. Department of Veterans Affairs (VA) has an ongoing project to integrate diagnostic images into its existing text-based hospital information system. High-quality images from cardiology, pulmonary medicine, gastroenterology, endoscopy, pathology, radiology, hematology and nuclear medicine can be displayed for clinicians quickly and conveniently on workstations throughout the hospital. As a part of this endeavor, diagnostic-quality computer generated 12-lead electrocardiograms, including both median and rhythm data, can be viewed as a part of the on-line patient record of an integrated hospital information system. Now computer generated graphics can be included in the longitudinal patient record. Incorporating generated graphics and images into a text based patient record is another step towards the next generation of integrated hospital information system with multimedia patient records.

District of Columbia↗
PubMed1993

The influence of atrial fibrillation on prognosis in mild to moderate heart failure. The V-HeFT Studies. The V-HeFT VA Cooperative Studies Group.

BACKGROUND: Atrial fibrillation occurs commonly in heart failure; however, its importance in terms of prognosis is controversial. METHODS AND RESULTS: We assessed the relation of atrial fibrillation on first Holter monitor to morbidity and mortality in mild to moderate heart failure in 632 patients in the Veterans Affairs Vasodilator-Heart Failure Trial (V-HeFT) I and 795 patients in V-HeFT II: Ninety-nine patients in atrial fibrillation and 533 patients in sinus rhythm were followed for a mean of 2.5 years (range, 6 months to 5.7 years) in V-HeFT I; 107 patients in atrial fibrillation and 688 patients in sinus rhythm in V-HeFT II were followed for a mean of 2.5 years (range, 6 months to 5.0 years). V-HeFT I compared treatment with prazosin, hydralazine-isosorbide dinitrate, and placebo, whereas V-HeFT II compared hydralazine-isosorbide dinitrate with enalapril. Follow-up evaluations included serial Holter monitors, serial metabolic exercise testing, hospitalization data, and clinical examinations. In V-HeFT I, cumulative mortality at 2 years was 0.34 for patients with atrial fibrillation and 0.30 for patients in sinus rhythm (p = 0.25). Overall cumulative mortality was 0.54 for atrial fibrillation patients and 0.64 for sinus rhythm patients (p = 0.86). In V-HeFT II, cumulative mortality at 2 years was 0.20 for patients with atrial fibrillation and 0.21 for patients with sinus rhythm (p = 0.68), and overall cumulative mortality was 0.46 for atrial fibrillation patients and 0.52 for those in sinus rhythm (p < 0.46). Sudden death was not increased with atrial fibrillation in V-HeFT I patients (p = 0.64) or in V-HeFT II (p = 0.68). By multivariate analysis, the relative mortality risk for atrial fibrillation was 0.95 in V-HeFT I and 0.76 in V-HeFT II: Metabolic exercise testing, showed no significant difference in mean change in peak oxygen consumption between patients with atrial fibrillation and those with sinus rhythm in V-HeFT I and a slight decrease late in V-HeFT II: Hospitalization rate for heart failure was not increased in either study. The embolic event rate was not increased for atrial fibrillation patients: 3% versus 4.9% of patients in sinus rhythm (p = 0.41) in V-HeFT I and 4.0% versus 6.0% in V-HeFT II patients (p = 0.44). A secondary analysis compared mortality of patients in atrial fibrillation with that of patients in sinus rhythm on all Holters: Mortality was not increased overall (p = 0.72 in V-HeFT I and p = 0.35 in V-HeFT II). CONCLUSIONS: Atrial fibrillation does not increase major morbidity or mortality in mild to moderate heart failure.

Atrial Fibrillation↗
PubMed1993

Enalapril decreases prevalence of ventricular tachycardia in patients with chronic congestive heart failure. The V-HeFT II VA Cooperative Studies Group.

BACKGROUND: Patients with heart failure have a high prevalence of serious arrhythmias and sudden cardiac-death. METHODS AND RESULTS: Male patients aged 18-75 years with chronic heart failure were randomized to enalapril or hydralazine-isosorbide dinitrate. Short-term (4-hour to 8-hour) Holter tape recordings were performed before randomization, at 3 months, at 1 year, and yearly thereafter. Of 804 patients randomized to therapy, 715 had Holters at baseline. Couplets were noted in 56% versus 60% and ventricular tachycardia (VT) (three or more consecutive ventricular premature beats) in 27% versus 29% of patients randomized to enalapril versus hydralazine-isosorbide dinitrate, respectively. The presence of VT at 3 months, 1 year, and 2 years predicted significantly higher mortality during the subsequent year (p < 0.0001, p < 0.001, and p < 0.037, respectively). In the enalapril group, VT prevalence decreased by 27% at 1 year (p < 0.02). A decrease in prevalence of VT was not seen in the hydralazine-isosorbide dinitrate group. New VT was seen in 11% of enalapril patients versus 24% of hydralazine-isosorbide dinitrate patients at 1 year (p < 0.002). When compared with hydralazine-isosorbide dinitrate at 1 and 2 years, there was a 52% and 49% reduction, respectively, in sudden deaths in the enalapril group. Thus, at 1 and 2 years, the decrease in sudden deaths in the enalapril group coincided with the decrease in VT prevalence and the decrease in new VT emergence. CONCLUSIONS: In patients with heart failure, VT and couplets predict increased mortality. When compared with hydralazine-isosorbide dinitrate, enalapril decreases both the persistence of baseline VT at 3 months and the emergence of new VT at 1 and 2 years. The reduction in VT prevalence parallels a reduction in sudden death. The effect of enalapril on survival over hydralazine-isosorbide dinitrate may be related to its ability to reduce prevalence of ventricular arrhythmia.

Death, Sudden, Cardiac↗
PubMed1992

Catheter ablation of hemodynamically compromising incessant atrioventricular tachycardia.

A 27-year-old woman was admitted to the Georgetown University Hospital with refractory hemodynamically compromising incessant atrioventricular tachycardia. A single left-sided accessory pathway was identified and successfully modified acutely. Endocardial delivery of direct current energy provided an extremely effective therapeutic intervention resulting in termination of atrioventricular tachycardia and restoration of stable hemodynamic status. Although a second ablation procedure was necessary to permanently interrupt accessory pathway conduction, the patient has remained free of symptoms without medications for 13 months.

Adult↗
PubMed1992

Congestive heart failure: survival trial of antiarrhythmic therapy (CHF STAT). The CHF STAT Investigators.

This study is a prospective, double-masked, randomized, clinical trial to determine the effect of anti-arrhythmic drug therapy on mortality in patients with congestive heart failure and ventricular arrhythmia. Patients will be assigned to receive either amiodarone or placebo. Eligible patients include those with ischemic and nonischemic congestive heart failure (New York Heart Association class III or VI) and with 10 or more ventricular premature beats per hour. All patients must have shortness of breath with minimal exertion or paroxysmal nocturnal dyspnea, a left ventricular internal dimension (LVIDd) by echocardiogram of 55 mm or greater (> or = 55 mm) or a CT ratio of greater than 0.5, and an ejection fraction of 40% of less. Patients will be entered into the study for 2.5 years and followed for an additional 2 years. Drug therapy will be continued for all patients throughout the entire study unless adverse reactions occur that necessitate individualized treatment. The expectation is that 674 patients are to be entered into the study from 25 participating centers. This sample size will allow for the detection of a 33% decrease in 2-year mortality (20% vs. 30%) in the treated patients as compared to those in the placebo group with a power of 0.90 and a two-sided alpha level of 0.05. Intermittent Holter monitoring, radionuclide ventriculograms, pulmonary function tests, echocardiograms, and blood tests, including arterial blood gases, will be required for each patient. The study analysis will address differences in total mortality, cardiac mortality, and sudden cardiac death between patients receiving anti-arrhythmic drug therapy and those receiving placebo. Other factors to be examined include the effects of antiarrhythmic therapy on suppression of arrhythmias, on ejection fraction, and relation of ischemic events to mortality.

Amiodarone↗
PubMed1991

Ventricular late potentials in myotonic dystrophy.

OBJECTIVE: To determine the prevalence of ventricular late potentials, as determined by signal-averaged electrocardiography, in patients with myotonic dystrophy. DESIGN: Cross sectional, with blinded analysis of all electrocardiographic data. SETTING: Outpatient departments of a Veterans Affairs medical center and a tertiary care private hospital. PARTICIPANTS: Twenty-four patients with myotonic dystrophy. Patients were excluded from the study if they had either a history suggestive of significant ventricular arrhythmias or electrocardiographic evidence of a bundle-branch block. Two comparison groups were also formed; one group included 44 healthy employees at the tertiary hospital and the other, 30 cardiac patients with inducible ventricular tachycardia. MAIN RESULTS: A time-domain analysis of the signal-averaged electrocardiograms showed that 75% of patients with myotonic dystrophy met one criterion for the presence of late potentials, 67% met two criteria, and 29% met all three criteria. Spectrotemporal mapping in these patients showed markedly abnormal spectral peaks with a mean factor of normality that was significantly lower than that of the normal volunteers; the frequency of electrocardiographic abnormalities approached that seen in patients with known ventricular tachycardia. The presence of late potentials correlated directly with the length of the PR interval and inversely with left ventricular fractional shortening. CONCLUSIONS: In our study, the prevalence of late potentials on signal-averaged electrocardiography in patients with myotonic dystrophy approached that seen in cardiac patients with inducible ventricular tachycardia. It is possible that ventricular arrhythmias play a role in the occurrence of sudden death in some patients with myotonic dystrophy.

Adult↗
PubMed1991

Sudden cardiac death after myocardial infarction.

Recent advances in the understanding of the mechanisms of sudden cardiac death have been paralleled by technical advances in diagnosis and treatment, involving ambulatory Holter monitoring and the use of implantable defibrillators. Risk factors predisposing toward sudden cardiac death in the postmyocardial infarction setting and in patients with congestive heart failure include the presence of ventricular ectopy [greater than 10 premature ventricular contractions (PVC) per hour], frequent episodes of ventricular pairs and nonsustained ventricular tachycardia on 24-hour Holter monitoring, and a depressed left ventricular ejection fraction. Additional risk factors for sudden cardiac death in coronary artery disease include arterial stenosis in coronary vessels supplying intact myocardium remote from the infarction site, the presence of late potentials on the signal averaged ECG, and attenuation of the normal variation in heart rate. The ability to induce sustained ventricular tachycardia (SVT) on electrophysiological testing is highly predictive of sudden cardiac death after myocardial infarction. Conversely, the ease of suppression of the induced tachycardia with antiarrhythmic agents is correlated with the risk of subsequent lethal ventricular arrhythmia. The detrimental effect of frequent ventricular ectopy (greater than 10 PVC/h) on survival in coronary artery disease is particularly pronounced in patients with moderately well preserved left ventricular function [ejection fraction (EF) greater than 30%], thereby suggesting that these patients may be better served by antiarrhythmic therapy than those with severely depressed left ventricular function.(ABSTRACT TRUNCATED AT 250 WORDS)

Death, Sudden↗
PubMed1991

Providing an integrated clinical data view in a hospital information system that manages multimedia data.

The VA's hospital information system, the Decentralized Hospital Computer Program (DHCP), is an integrated system based on a powerful set of software tools with shared data accessible from any of its application modules. It includes many functionally specific application subsystems such as laboratory, pharmacy, radiology, and dietetics. Physicians need applications that cross these application boundaries to provide useful and convenient patient data. One of these multi-specialty applications, the DHCP Imaging System, integrates multimedia data to provide clinicians with comprehensive patient-oriented information. User requirements for cross-disciplinary image access can be studied to define needs for similar text data access. Integration approaches must be evaluated both for their ability to deliver patient-oriented text data rapidly and their ability to integrate multimedia data objects. Several potential integration approaches are described as they relate to the DHCP Imaging System.

Computer Communication Networks↗
PubMed1990

Left ventricular hypertrophy in men with normal blood pressure: relation to exaggerated blood pressure response to exercise.

OBJECTIVE: To determine whether normal, nonhypertensive subjects who have unusually large increases of systolic blood pressure with exercise have left ventricular hypertrophy (LVH). DESIGN: Case-comparison using echocardiography as a criterion standard for measurement of left ventricular mass and the diagnosis of LVH. SETTING: Population-based health fitness screening program and referral Veterans Affairs Hospital. SUBJECTS: Thirty-nine men (average age, 44.6 +/- 8.5 years; range, 34 to 71 years) were studied, including 25 participants in a health fitness screening program and an additional 14 normal men with atypical chest pain. Twenty-two subjects with a systolic blood pressure during peak exercise of 210 mm Hg or greater were compared with 17 others with systolic pressure less than 210 mm Hg during exercise. MEASUREMENTS AND MAIN RESULTS: Left ventricular hypertrophy (left ventricular mass index greater than 134 g/m2) was found in 14 of 22 men with a systolic blood pressure of 210 mm Hg or greater (present in 6.3% of normotensive healthy male volunteers in a health screening program) but in only 1 person with a lower exercise blood pressure. Left ventricular mass index was linearly correlated (r = 0.65, n = 39, P less than 0.001) with maximum exercise blood pressure. Whereas LVH was mild in about 50%, substantial LVH was present in the others. The presence of LVH was not related to superior physical conditioning and was accompanied by increased left atrial size suggesting impaired left ventricular filling. CONCLUSIONS: Even in the absence of hypertension, exaggerated blood pressure responses during exercise testing suggest a probability of 0.64 (95% CI, 0.41 to 0.83) of LVH, a finding associated with the cardiac "end-organ" manifestations of hypertension.

Adult↗