Search PubMed⌕ Search

Biomedical subjects

K L Baughman

Publications and source records attributed to K L Baughman.

At least 19 recordsLinked to original sources
PubMed2003

Peripartum cardiomyopathy.

Peripartum cardiomyopathy is a rare and life-threatening disease of unknown etiology. This diagnosis should be limited to previously healthy women who present with congestive heart failure (CHF) and decreased left ventricular systolic function in the last month of pregnancy or within 5 months after delivery. The diagnosis is not made in the presence of other causes of cardiac dysfunction. Patients who fail to demonstrate improvement within 2 weeks after the onset of symptoms should be evaluated for myocarditis. The type and duration of heart failure treatment is determined by the patient's heart performance at rest and with exertion. Those with normal left ventricular function at rest and with exercise or dobutamine have a good prognosis, and their medical therapy can be tapered off or discontinued over a period of 6-12 months. Patients with normal ventricular function at rest, but abnormal response to exercise should be treated for long periods of time with angiotensin converting enzyme (ACE) inhibitors or beta-blockers. Patients who continue to have depressed LV function have a poor prognosis and require treatment with appropriate medications for the rest of their lives. Pharmacological treatment includes ACE inhibitors, beta-blocking agents, diuretics, digoxin, and anticoagulation. Angiotensin converting enzyme inhibitors are used only after delivery because of their teratogenic effects. Patients who fail to recover may require inotropic therapy, intra-aortic balloon pump and left ventricular assist device as needed. Cardiac transplantation should be considered for patients who fail therapy.

Adult↗
PubMed2001

Chronic active myocarditis following acute Bartonella henselae infection (cat scratch disease).

An association between Bartonella infection and myocardial inflammation has not been previously reported. We document a case of a healthy young man who developed chronic active myocarditis after infection with Bartonella henselae (cat scratch disease). He progressed to severe heart failure and underwent orthotopic heart transplantation. Bartonella henselae, therefore, should be included among the list of infectious agents associated with chronic active myocarditis.

Acute Disease↗
PubMed2000

Underlying causes and long-term survival in patients with initially unexplained cardiomyopathy.

BACKGROUND: Previous studies of the prognosis of patients with heart failure due to cardiomyopathy categorized patients according to whether they had ischemic or nonischemic disease. The prognostic value of identifying more specific underlying causes of cardiomyopathy is unknown. METHODS: We evaluated the outcomes of 1230 patients with cardiomyopathy. The patients were grouped into the following categories according to underlying cause: idiopathic cardiomyopathy (616 patients), peripartum cardiomyopathy (51); and cardiomyopathy due to myocarditis (111), ischemic heart disease (91), infiltrative myocardial disease (59), hypertension (49), human immunodeficiency virus (HIV) infection (45), connective-tissue disease (39), substance abuse (37), therapy with doxorubicin (15), and other causes (117). Cox proportional-hazards analysis was used to assess the association between the underlying cause of cardiomyopathy and survival. RESULTS: During a mean follow-up of 4.4 years, 417 patients died and 57 underwent cardiac transplantation. As compared with the patients with idiopathic cardiomyopathy, the patients with peripartum cardiomyopathy had better survival (adjusted hazard ratio for death, 0.31; 95 percent confidence interval, 0.09 to 0.98), and survival was significantly worse among the patients with cardiomyopathy due to infiltrative myocardial disease (adjusted hazard ratio, 4.40; 95 percent confidence interval, 3.04 to 6.39), HIV infection (adjusted hazard ratio, 5.86; 95 percent confidence interval, 3.92 to 8.77), therapy with doxorubicin (adjusted hazard ratio, 3.46; 95 percent confidence interval, 1.67 to 7.18), and ischemic heart disease (adjusted hazard ratio, 1.52; 95 percent confidence interval, 1.07 to 2.17). CONCLUSIONS: The underlying cause of heart failure has prognostic value in patients with unexplained cardiomyopathy. Patients with peripartum cardiomyopathy appear to have a better prognosis than those with other forms of cardiomyopathy. Patients with cardiomyopathy due to infiltrative myocardial diseases, HIV infection, or doxorubicin therapy have an especially poor prognosis.

Adult↗
PubMed2000

Long-term outcome of fulminant myocarditis as compared with acute (nonfulminant) myocarditis.

BACKGROUND: Lymphocytic myocarditis causes left ventricular dysfunction that may be persistent or reversible. There are no clinical criteria that predict which patients will recover ventricular function and which cases will progress to dilated cardiomyopathy. We hypothesized that patients with fulminant myocarditis may have a better long-term prognosis than those with acute (nonfulminant) myocarditis. METHODS: We identified 147 patients considered to have myocarditis according to the findings on endomyocardial biopsy and the Dallas histopathological criteria. Fulminant myocarditis was diagnosed on the basis of clinical features at presentation, including the presence of severe hemodynamic compromise, rapid onset of symptoms, and fever. Patients with acute myocarditis did not have these features. The incidence of the end point of this study, death or heart transplantation, was ascertained by contact with the patient or the patient's family or by a search of the National Death Index. The average period of follow-up was 5.6 years. RESULTS: A total of 15 patients met the criteria for fulminant myocarditis, and 132 met the criteria for acute myocarditis. Among the patients with fulminant myocarditis, 93 percent were alive without having received a heart transplant 11 years after biopsy (95 percent confidence interval, 59 to 99 percent), as compared with only 45 percent of those with acute myocarditis (95 percent confidence interval, 30 to 58 percent; P=0.05 by the log-rank test). Fulminant myocarditis was an independent predictor of survival after adjustments were made for age, histopathological findings, and hemodynamic variables. The rate of transplantation-free survival did not differ significantly between the patients considered to have borderline myocarditis and those considered to have active myocarditis according to the Dallas histopathological criteria. CONCLUSIONS: Fulminant myocarditis is a distinct clinical entity with an excellent long-term prognosis. Aggressive hemodynamic support is warranted for patients with this condition.

Acute Disease↗
PubMed2000

Peripartum cardiomyopathy: National Heart, Lung, and Blood Institute and Office of Rare Diseases (National Institutes of Health) workshop recommendations and review.

OBJECTIVE: Peripartum cardiomyopathy (PPCM) is a rare life-threatening cardiomyopathy of unknown cause that occurs in the peripartum period in previously healthy women. In April 1997, the National Heart, Lung, and Blood Institute (NHLBI) and the Office of Rare Diseases of the National Institutes of Health (NIH) convened a Workshop on Peripartum Cardiomyopathy to foster a systematic review of information and to develop recommendations for research and education. PARTICIPANTS: Fourteen workshop participants were selected by NHLBI staff and represented cardiovascular medicine, obstetrics, immunology, and pathology. A representative subgroup of 8 participants and NHLBI staff formed the writing group for this article and updated the literature on which the conclusions were based. The workshop was an open meeting, consistent with NIH policy. EVIDENCE: Data presented at the workshop were augmented by a MEDLINE search for English-language articles published from 1966 to July 1999, using the terms peripartum cardiomyopathy, cardiomyopathy, and pregnancy. Articles on the epidemiology, pathogenesis, pathophysiology, diagnosis, treatment, and prognosis of PPCM were included. RECOMMENDATION PROCESS: After discussion of data presented, workshop participants agreed on a standardized definition of PPCM, a general clinical approach, and the need for a registry to provide an infrastructure for future research. CONCLUSIONS: Peripartum cardiomyopathy is a rare lethal disease about which little is known. Diagnosis is confined to a narrow period and requires echocardiographic evidence of left ventricular systolic dysfunction. Symptomatic patients should receive standard therapy for heart failure, managed by a multidisciplinary team. If subsequent pregnancies occur, they should be managed in collaboration with a high-risk perinatal center. Systematic data collection is required to answer important questions about incidence, treatment, and prognosis.

Cardiomyopathies↗
PubMed2000

Echocardiographic findings in fulminant and acute myocarditis.

OBJECTIVES: We sought to use echocardiography to assess the presentation and potential for recovery of left ventricular (LV) function of patients with fulminant myocarditis compared with those with acute myocarditis. BACKGROUND: The clinical course of patients with myocarditis remains poorly defined. We have previously proposed a classification that provides prognostic information in myocarditis patients. Fulminant myocarditis causes a distinct onset of illness and severe hemodynamic compromise, whereas acute myocarditis has an indistinct presentation, less severe hemodynamic compromise and a greater likelihood of progression to dilated cardiomyopathy. METHODS: Echocardiography was performed at presentation and at six months to test the hypothesis that fulminant (n = 11) or acute (n = 43) myocarditis could be distinguished morphologically. RESULTS: Patients with both fulminant (fractional shortening 19 +/- 4%) and acute myocarditis (17 +/- 7%) had LV systolic dysfunction. Patients with fulminant myocarditis had near normal LV diastolic dimensions (5.3 +/- 0.9 cm) but increased septal thickness (1.2 +/- 0.2 cm) at presentation, while those with acute myocarditis had increased diastolic dimensions (6.1 +/- 0.8 cm, p < 0.01 vs. fulminant) but normal septal thickness (1.0 +/- 0.1 cm, p = 0.01 vs. fulminant). At six months, patients with fulminant myocarditis had dramatic improvement in fractional shortening (30 +/- 8%) compared with no improvement in patients with acute myocarditis (19 +/- 7%, p < 0.01 for interaction between time and type of myocarditis). CONCLUSIONS: Fulminant myocarditis is distinguishable from acute myocarditis by echocardiography. Patients with fulminant myocarditis exhibit a substantial improvement in ventricular function at six months compared with those with acute myocarditis. Echocardiography has value in classifying patients with myocarditis and may provide prognostic information.

Acute Disease↗
PubMed2000

Myocarditis and long-term survival in peripartum cardiomyopathy.

BACKGROUND: The reported mortality rate of peripartum cardiomyopathy (PPCM) is high, although the potential for spontaneous recovery of ventricular function is well established. The prevalence of myocarditis in PPCM has varied widely between studies. The purposes of this study were to define the long-term prognosis in a referral population of patients with PPCM, to determine the prevalence of myocarditis on endomyocardial biopsy in this population, and to identify clinical variables associated with poor outcome. METHODS: We analyzed clinical, echocardiographic, hemodynamic, and histologic features of 42 women with PPCM evaluated at our institution over a 15-year period. Each patient underwent an extensive evaluation, including echocardiography, endomyocardial biopsy, and right heart catheterization. Data were analyzed to identify features at initial examination associated with the combined end point of death or cardiac transplantation by the use of Kaplan-Meier survival curves and a Cox proportional hazards model. RESULTS: Three (7%) patients died and 3 (7%) patients underwent heart transplantation during a median follow-up of 8.6 years. Endomyocardial biopsy demonstrated a high prevalence of myocarditis (62%), but the presence or absence of myocarditis was not associated with survival. Of the prespecified variables assessed, only decreased left ventricular stroke work index was associated with worsened outcome. CONCLUSIONS: In patients with PPCM, (1) long-term survival is better than has been historically reported, (2) the prevalence of myocarditis is high, and (3) decreased left ventricular stroke work index is associated with worse clinical outcomes.

Adult↗
PubMed1999

The spectrum of dilated cardiomyopathy. The Johns Hopkins experience with 1,278 patients.

This report describes the evaluation of 1,278 patients referred to The Johns Hopkins Hospital with dilated cardiomyopathy. After a careful history and physical examination, selected laboratory tests, and endomyocardial biopsy, a specific diagnosis was made in 49% of cases. In 16% of cases the biopsy demonstrated a specific histologic diagnosis. Myocarditis and coronary artery disease were the most frequent specific diagnoses; 51% of patients were classified as idiopathic. Thus a rigorous and systematic search can demonstrate an underlying cause for approximately one-half of patients with unexplained cardiomyopathy. Endomyocardial biopsy plays a crucial role in this evaluation. Six cases are presented which demonstrate the utility of endomyocardial biopsy in specific clinical situations. In addition to its routine use in monitoring rejection in heart transplant recipients, endomyocardial biopsy is indicated in the evaluation of possible infiltrative cardiomyopathy, in differentiating restrictive cardiomyopathy from constrictive pericarditis, and in diagnosing and monitoring doxorubicin cardiotoxicity. The importance of diagnosing myocarditis remains controversial, and disagreement persists about the utility of immunosuppressive therapy in these patients. A combination of clinical and histologic features can divide patients with myocarditis into 4 subgroups--acute, fulminant, chronic active, and chronic persistent. This classification provides prognostic information and may identify those patients who may respond to immunosuppression, as well as those likely to have adverse outcomes from such treatment. The continued development of novel molecular techniques may allow endomyocardial biopsy to provide greater prognostic and therapeutic information in the future.

Adolescent↗
PubMed1998

Mechanism of acute mechanical benefit from VDD pacing in hypertrophied heart: similarity of responses in hypertrophic cardiomyopathy and hypertensive heart disease.

BACKGROUND: Dual-chamber pacing can improve symptoms in hypertrophic cardiomyopathy (HCM), but the mechanism remains unclear. We hypothesized that pacing generates discoordinate contraction and a rightward shift of the end-systolic pressure-volume relation (ESPVR) and that benefits from this mechanism do not depend on the presence of resting outflow pressure gradients or obstruction. METHODS AND RESULTS: Eleven patients with NYHA class III symptoms, 5 with HCM, and 6 with hypertensive hypertrophy and cavity obliteration, were studied by invasive conductance catheter methods. No patient had coronary artery or primary valvular disease. Pressure-volume relations were recorded before and during VDD pacing by use of a short (75-millisecond) PR interval to achieve preexcitation. Left ventricular cavity pressure was simultaneously recorded at basal and apical sites, with pressure at the basal site used to generate the ESPVRs. VDD pacing shifted the ESPVR rightward, increasing end-systolic volume by 45% (range, 17% to 151%; P=0.002). Resting and provokable gradients declined by 20% (range, -56% to +3%) and 30% (range, -65% to -12%), respectively (P<0.05). Preload declined by 3% to 10% because of the short PR interval. Preload-corrected contractility indexes and myocardial workload declined by approximately 10% (P<0.001). Diastolic compliance and relaxation time were unchanged. Pacing made apical pressure-volume loops discoordinate, limiting cavity obliteration and reducing distal systolic pressures. Results in both patient groups were similar. CONCLUSIONS: VDD pacing shifts the ESPVR rightward in HCM patients with cavity obliteration with or without obstruction, increasing end-systolic volumes and reducing apical cavity compression and cardiac work. These effects likely contribute to reduced metabolic demand and improved symptoms.

Adult↗
PubMed1997

Beat-to-beat QT interval variability: novel evidence for repolarization lability in ischemic and nonischemic dilated cardiomyopathy.

BACKGROUND: Dilated cardiomyopathy (DCM) is associated with a high incidence of malignant ventricular arrhythmias and sudden death. Abnormalities in repolarization of ventricular myocardium have been implicated in the development of these arrhythmias. Spatial heterogeneity in repolarization has been studied in DCM, but temporal fluctuations in repolarization in this setting have been largely ignored. We sought to test the hypothesis that beat-to-beat QT interval variability is increased in DCM patients compared with control subjects. METHODS AND RESULTS: Eighty-three patients with ischemic and nonischemic DCM and 60 control subjects served as the study population. Beat-to-beat QT interval variability was measured by automated analysis on the basis of 256-second records of the surface ECG. A QT variability index (QTVI) was calculated for each subject as the logarithm of the ratio of normalized QT variance to heart rate variance. The coherence between heart rate and QT interval fluctuations was determined by spectral analysis. In patients, ejection fractions were assessed by echocardiography or ventriculography, and spatial QT dispersion was determined from the standard 12-lead ECG. DCM patients had greater QT variance than control subjects (60.4+/-63.1 versus 25.7+/-24.8 ms2, P<.0001) despite reduced heart rate variance (6.7+/-7.8 versus 10.5+/-10.4 bpm2, P=.01). The QTVI was higher in DCM patients than in control subjects, with a high degree of significance (-0.43+/-0.71 versus -1.29+/-0.51, P<10[-12]). QTVI did not correlate with ejection fraction or spatial QT dispersion but did depend on New York Heart Association functional class. QTVI did not differ between DCM patients with ischemic and those with nonischemic origin. Coherence between heart rate and QT interval fluctuations at physiological frequencies was lower in DCM patients compared with control subjects (0.28+/-0.14 versus 0.39+/-0.18, P<.0001). CONCLUSIONS: DCM is associated with beat-to-beat fluctuations in QT interval that are larger than normal and uncoupled from variations in heart rate. QT interval variability increases with worsening functional class but is independent of ejection fraction. These data indicate that DCM leads to temporal lability in ventricular repolarization.

Adult↗
PubMed1996

Marked discordance between dynamic and passive diastolic pressure-volume relations in idiopathic hypertrophic cardiomyopathy.

BACKGROUND: Dynamic diastolic pressure-volume curves measured during filling (PVR fill) in patients with idiopathic hypertrophic cardiomyopathy (HCM) are often considerably shallower than would be anticipated if one assumed high chamber stiffness. We hypothesized that these curves deviate markedly from the passive end-diastolic pressure-volume relation (EDPVR) and explored the mechanisms for such a discordance. METHODS AND RESULTS: We used invasive pressure-volume analysis and conductance catheter methodology to study 42 patients. Nine had HCM, and the remaining patients comprised three comparison groups: 11 with normal left ventricular (LV) function, 13 with LV hypertrophy secondary to chronic hypertension (LVH-HTN), and 9 with idiopathic dilated cardiomyopathy (DCM). EDPVRs were recorded during balloon catheter obstruction of inferior vena cava inflow. In normal subjects, LVH-HTN patients, and DCM patients, PVR fill curves deviated only slightly from the passive EDPVR. In striking contrast, HCM patients displayed a flat PVR fill that was very different from the steep EDPVR. On reduction of preload, PVR fill relations in HCM shifted downward in parallel, with a net pressure decline at the same chamber volume of -10+/-4 mm Hg. This staircaselike shift was much less in the other patient groups (-2+/-2 mm Hg; P<.001). The unusual behavior in HCM could not be attributed directly to increased viscosity, enhanced pericardial constraint, or preload dependence of isovolumic relaxation. Regional heterogeneity of relaxation may play a role; however, we speculate that the major mechanism relates to the unique fiber and chamber architecture seen with HCM and possibly to enhanced ventricular interaction. CONCLUSIONS: Elevated LV filling pressures in HCM are not due simply to a stiff cavity but also reflect a major influence of offset pressures that vary with chamber loading. The large disparity between flat pressure-volume relations during filling and steep end-diastolic relations appears unique to HCM. This indicates that caution should be used in the interpretation of stiffness results derived from steady-state data and suggests that therapies that alter cavity geometry and/or reduce interaction may markedly influence LV diastolic pressures in HCM.

Adult↗
PubMed1996

Epidemiology of idiopathic dilated cardiomyopathy in the elderly: pooled results from two case-control studies.

Although idiopathic dilated cardiomyopathy is often viewed as an affliction of young of middle-aged adults, morbidity and mortality rates from idiopathic dilated cardiomyopathy rise sharply with age and are the highest in the elderly. To learn more about the determinants of this increasingly important cause of heart failure in the elderly, the authors conducted a pooled analysis of data from two case-control studies of idiopathic dilated cardiomyopathy carried out in Baltimore, Maryland (1984-1986), and in Washington, DC (1990-1992). Identical diagnostic criteria and interviewing procedures had been used in both studies. All of the cases of idiopathic dilated cardiomyopathy had evidence of ventricular dilation and hypokinesis, with a left ventricular ejection fraction of < 40%. Cases with a history of coronary artery disease were excluded along with those with known secondary forms of cardiomyopathy, Up to two neighborhood controls of the same sex and appropriate age (+/- 5 years) were selected for each case using a random digit dialing technique. The subjects or a suitable surrogate was interviewed by telephone to obtain medical history information. The present analysis was limited to 94 cases and 152 matched controls who were at least 60 years of age. Conditional logistic regression methods were used in the analysis. Significant associations were observed with lower educational attainment and a history of hypertension (P < 0.05). The association with hypertension (relative odds = 2.2, 95% confidence interval 1.1-4.6) persisted after adjustment for race, education, and diabetes and was not accounted for by coronary angiography utilization patterns. The association with diabetes was of borderline significance (p < 0.10). The pattern of risk factors identified in this analysis may allow for the early identification of elderly persons who are at increased risk of idiopathic dilated cardiomyopathy.

Age Distribution↗