Remission of recurrent gastrointestinal bleeding after septal reduction therapy in patients with hypertrophic obstructive cardiomyopathy-associated acquired von Willebrand syndrome.

BACKGROUND: Gastrointestinal hemorrhage is considered to be a severe complication of von Willebrand disease. The optimal therapy for acquired von Willebrand syndrome and severe gastrointestinal bleeding with hypertrophic cardiomyopathy is undefined. PATIENTS/METHODS: Seventy-seven patients (median age, 67 years; interquartile range [IQR], 56-75 years; 49% women) with hypertrophic cardiomyopathy underwent von Willebrand factor multimer testing and acquisition of bleeding history. Bleeding was detected in 27 (36%) (median age, 74 years; IQR 66-76 years; 74% women), 20 with gastrointestinal bleeding, including 11 women with transfusion dependence. In these 11 women, the median duration of transfusion dependency was 36 months (IQR 18-44 months), and the median number of transfusions required was 25 (IQR 20-38). Two patients had undergone bowel resection for bleeding, one of them twice. Seven patients showed angiodysplasia, and the remainder had no endoscopic lesion. Bleeding recurred after bowel surgery or endoscopic intervention and medical therapy for hypertrophic cardiomyopathy in 10 of 11 patients. Two patients had septal myectomy, and six patients underwent alcohol septal ablation. With the exception of one patient in whom a significant gradient persisted after septal ablation, after the periprocedural period, patients after septal reduction therapy remained free of recurrent bleeding and need for transfusions. CONCLUSION: Acquired von Willebrand syndrome is common in hypertrophic cardiomyopathy. Gastrointestinal bleeding often recurs after endoscopic therapy, but may be relieved by structural cardiac repair.

Shear stress-associated acquired von Willebrand syndrome in patients with mitral regurgitation.

BACKGROUND: Mitral valve regurgitation is associated with an acquired hemostatic defect. OBJECTIVE: We sought to assess the prevalence and severity of acquired von Willebrand syndrome in patients with native valve mitral regurgitation (MR). PATIENTS/METHODS: Fifty-three patients were prospectively observed with bleeding questionnaires and laboratory tests when undergoing an echocardiographic assessment of MR. In patients referred for mitral valve surgery, testing was repeated postoperatively. RESULTS: Echocardiography identified 13 patients with mild MR, 14 with moderate MR, and 26 with severe MR. Among patients with mild, moderate or severe MR, loss of the highest molecular weight von Willebrand factor (VWF) multimers occurred in 8%, 64%, and 85%, respectively, median platelet function analyzer collagen ADP closure times (PFA-CADPs) were 84 s (interquartile range [IQR] 73-96 s), 156 s (IQR 104-181 s), and 190 s (IQR 157-279 s), respectively, and the ratios of VWF latex activity to antigen were 0.92 (IQR 0.83-0.97), 0.85 (IQR 0.76-0.89), and 0.79 (IQR 0.75-0.82), respectively (all P < 0.001). Nine patients reported clinically significant bleeding, and seven had intestinal angiodysplasia and transfusion-dependent gastrointestinal bleeding (Heyde syndrome), with the median number of transfusions required being 20 (IQR 10-33; range 4-50). In patients who underwent mitral valve repair (n = 13) or replacement (n = 7), all measures of VWF function reported above improved significantly. CONCLUSION: The high-shear environment of moderate to severe MR is sufficient to produce prevalent perturbations in VWF activity. Acquired von Willebrand syndrome may occur in this setting, and appears to be reversible with mitral valve surgery.

Left atrial diameter in nonvalvular atrial fibrillation: An echocardiographic study. Stroke Prevention in Atrial Fibrillation Investigators.

BACKGROUND: The left atrium (LA) is usually enlarged in patients with nonvalvular atrial fibrillation (AF), but factors associated with LA diameter are incompletely defined. METHODS AND RESULTS: This transthoracic echocardiographic cohort study includes 3465 participants with nonvalvular AF in 3 multicenter clinical trials. LA diameter determined by M-mode echocardiography was correlated with clinical and echocardiographic features by cross-sectional multivariate regression analyses. The mean LA diameter was 47 +/- 8 mm, on average 6 mm larger in those with AF at the time of echocardiography than in those with sinus rhythm (48 vs 42 mm, P <. 001). Patient age and body weight were independently predictive of LA diameter (P <.0001), but sex, body surface area, and body mass index were not. The estimated independent contribution of atrial rhythm to LA diameter was approximately 2.5 mm. Prolonged duration of AF, left ventricular dilatation and increased muscle mass, mitral regurgitation, annular calcification, and hypertension were additional independent predictors of LA diameter. CONCLUSIONS: Multiple factors appear to contribute to LA enlargement in patients with nonvalvular AF, including the presence and persistence of the dysrhythmia.

The relationship between cardiothoracic ratio and left ventricular ejection fraction in congestive heart failure. Digitalis Investigation Group.

BACKGROUND: Left ventricular ejection fraction (EF) is a valuable prognostic index in patients with congestive heart failure (CHF). Although EF can be readily measured, many clinicians use roentgenographic heart size as a clue to differentiate systolic from diastolic dysfunction, even in the absence of solid supportive data. OBJECTIVE: To test the hypothesis that the cardiothoracic ratio (CTR) measured from the chest roentgenogram can be used to estimate left ventricular EF in individuals with CHF. METHODS: To answer this question, the database of the Digitalis Investigation Group trial was used. The CTR, determined using the Danzer method, and quantitative EF, measured locally using angiographic, radionuclide, or 2-dimensional echocardiographic techniques, were compared in 7476 patients with clinical CHF (New York Heart Association functional classes I-IV) due to acquired left-sided cardiac disease of ischemic, hypertensive, idiopathic, and alcohol-related causes. RESULTS: Mean (+/-SD) CTR for the cohort was 0.53+/-.07. Mean (+/-SD) EF was 31.7%+/-12.2%. A weak, negative correlation between CTR and EF was observed (r=-0.176). Similar findings were obtained when the results were stratified by cause of CHF, presence of clinically defined right ventricular dysfunction, and method of EF measurement. Categorical analysis failed to yield a CTR cutoff point that facilitated useful segregation of individuals with an EF greater than 35% or 35% and below; greater than 40% or 40% and below; and greater than 45% or 45% and below in any patient group. CONCLUSIONS: Although a weak, negative correlation exists between CTR and EF, this relationship does not allow for accurate determination of systolic function in individual patients with CHF. Considering the morbidity and mortality associated with CHF, and the clinical implications of systolic function in this syndrome, direct measurement of EF is recommended.

F-amplitude, left atrial appendage velocity, and thromboembolic risk in nonrheumatic atrial fibrillation. Stroke Prevention in Atrial Fibrillation Investigators.

BACKGROUND: Reduced left atrial appendage velocity (LAAV) has been identified as a marker for thromboembolism in patients with atrial fibrillation. HYPOTHESIS: It was postulated that electrocardiographic (ECG) F-wave amplitude would correlate with LAAV, and inversely with the risk of thromboembolism in patients with atrial fibrillation. METHODS: In all, 53 patients with nonrheumatic (NRAF) and 7 patients with rheumatic (RAF) atrial fibrillation underwent assessment of maximum LAAV, which was correlated to the maximum ECG F-wave voltage from lead V1 (F(max)). In 450 NRAF patients on neither aspirin nor warfarin, the relationship between F(max) and thromboembolic risk was assessed over an average follow-up of 1.3 years. RESULTS: F(max) did not correlate with LAAV (r = 0.2, p = 0.07). Patients with intermittent atrial fibrillation (n = 123) had smaller F(max) amplitude than patients with constant atrial fibrillation (n = 327) (mean 0.73 vs. 0.88 mV-1, p = 0.001). F(max) amplitude was not related to a history of hypertension, systolic blood pressure, duration of NRAF, abnormal transthoracic echocardiographic left ventricular (LV) systolic function or left atrial (LA) diameter. There was a strong trend for increased LV mass being related to smaller F(max) amplitude after adjusting for body surface area (p = 0.06). F(max) amplitude was not correlated with risk of embolic events, including only those events presumed by a panel of case-blinded neurologists to be cardioembolic. CONCLUSIONS: F(max) amplitude in NRAF is smaller in patients with intermittent versus constant AF. It does not correlate with LAAV, LA size, increased LV mass, or systolic dysfunction, hypertension, or risk of embolism. Therefore, F(max) amplitude may not be used as a surrogate for LAAV, or as a measure of thromboembolic risk in NRAF.

Management of atrial fibrillation in adults: prevention of thromboembolism and symptomatic treatment.

Because of its prevalence in the population and its associated underlying diseases and morbidity, atrial fibrillation (AF) is an important and costly health problem. Advancing age, diabetes, heart failure, valvular disease, hypertension, and myocardial infarction predict the occurrence of AF within a population. The management of AF is complex and involves prevention of thromboembolic complications and treatment of arrhythmia-related symptoms. Stroke occurs in 4.5% of untreated patients with AF per year. Independent risk factors for stroke in nonrheumatic patients with AF are advanced age; a history of prior embolism, hypertension, or diabetes; and echocardiographic findings of left atrial enlargement and left ventricular dysfunction. Warfarin decreases stroke by two-thirds and death by one-third; aspirin is only about half as effective overall and is insufficient therapy for those with risk factors for stroke. Options for thromboembolic prophylaxis are use of warfarin for all in whom it is safe or, alternatively, warfarin for those with risk factors and aspirin for those without risk factors. One-half of the patients with AF are 75 years of age or older. The uniform applicability and relative safety of warfarin therapy in this age-group are controversial. Specific therapy for the arrhythmia should be dictated by the need to control symptoms. Symptomatic treatments include rate-control medications and strategies designed to terminate and prevent arrhythmia recurrence. Digoxin, beta-adrenergic blockers, verapamil, and diltiazem slow excessive ventricular rates in patients with AF and may favorably manage comorbid conditions. The efficacy of anti-arrhythmic medications is only 40 to 70% per year in preventing recurrences of AF, and these agents, except amiodarone, may increase the risk of sudden death in patients with certain types of organic heart disease and AF. The use of nonpharmacologic symptomatic therapies such as atrioventricular node modification or ablation with a rate-response pacemaker or surgical intervention is increasing.

Nocturnal dyspnea and atrial fibrillation predict Cheyne-Stokes respirations in patients with congestive heart failure.

BACKGROUND: Cheyne-Stokes respirations have frequently been noted in highly selected groups of patients with congestive heart failure, but their prevalence in an unselected population with congestive heart failure is undefined. METHODS: One hundred consecutive unselected outpatients or stable inpatients with clinical congestive heart failure encountered by three clinical cardiologists during a 6-month period were screened for Cheyne-Stokes respirations with overnight oximetry. RESULTS: The mean age (+/- SD) of the patients was 70 +/- 8.6 years. Of the 100 patients, 33% had had previous coronary bypass surgery, 77% were men, 57% had hypertension, and 32% had atrial fibrillation. The mean ejection fraction (+/- SD) was 34% +/- 13%. Periodic breathing was assessed qualitatively as Cheyne-Stokes respirations in 27% of patients, nonspecific sleep-disordered breathing (apneas and/or hypopneas) in 43%, and normal in 30%. For patients with Cheyne-Stokes respirations, patients with nonspecific sleep-disordered breathing, and normal subjects, the mean numbers of oxyhemoglobin desaturation events per hour were 24, 10, and 2, and the total numbers of desaturations of 4% or more that lasted less than 3 minutes were 172, 74, and 13. Independent predictors of Cheyne-Stokes respirations vs non-Cheyne-Stokes respirations included a history of nocturnal dyspnea (odds ratio, 4.00; 95% confidence interval, 1.33 to 12.04; P = .01) and atrial fibrillation (odds ratio, 3.24; 95% confidence interval, 1.21 to 8.48; P = .02). CONCLUSIONS: Cheyne-Stokes respirations and nonspecific sleep-disordered breathing are common in unselected patients with congestive heart failure, and Cheyne-Stokes respirations are predicted by a history of nocturnal dyspnea and the presence of atrial fibrillation. Techniques designed to modify the nocturnal breathing pattern of patients with congestive heart failure may be applicable to a large portion of the congestive heart failure population.

Improved detection of silent cardiac ischemia with a 12-lead portable microprocessor-driven real-time electrocardiographic monitor.

OBJECTIVE: To compare a microprocessor-driven real-time 12-lead electrocardiographic monitoring device with Holter monitoring for detection of ischemia. DESIGN: Electrocardiographic monitoring was conducted in 110 patients at bed rest or undergoing surgical procedures. MATERIAL AND METHODS: In three groups of patients, simultaneous monitoring with a 12-lead real-time device and a 2-channel Holter system was performed to detect ischemic episodes. The differences in the number of ischemic events and the total time of ischemia revealed by the two devices were analyzed statistically. RESULTS: In patients with coronary artery disease, more ischemic ST-segment shifts were detected by the 12-lead device than by Holter monitoring (44 versus 16 events; P < 0.05). Total time of ischemia was also greater with the 12-lead device (879 versus 273 minutes; P < 0.05). Ischemia was detected by both techniques in 6 patients, only by the 12-lead device in 12, and only by Holter monitoring in 1. Neither device detected ischemia in control subjects. The 12-lead device had an advantage in detecting inferior ischemia, and it identified an additional 13 patients with unstable angina who had changes in T-wave polarity but did not exhibit ST-segment shifts. CONCLUSION: The 12-lead real-time electrocardiographic monitoring device is superior to Holter monitoring in detecting and facilitating real-time identification of myocardial ischemia in patients at bed rest.

Multimedia computer-assisted instruction in cardiology.

BACKGROUND: Medical education faces problems caused by increasing restraints on resources. A multicenter consortium combined simulation and multimedia computer-assisted instruction (MCAI) to develop unique interactive teaching programs that can address a number of these problems. We describe the consortium, the MCAI system, the programs, and a multicenter evaluation of technical and educational performance. METHODS: The MCAI system uses computer-controlled access to full-screen, full-motion, and full-color laser disc video in combination with digitized sound, images, and graphics stored on removable media. The Socratic teaching method enhances interaction and guides learners through the patient's history, cardiovascular physical examination, laboratory evaluation, and therapy. Self-instruction and instructor-led modes of function are possible. The first five programs, based on simulations of specific cardiology problems, were distributed to four medical centers. Questionnaires evaluated technical function and medical student opinions, while behaviors and scores were automatically tracked and tabulated by program administration software. RESULTS: The MCAI system functioned reliably and accurately in all modes and at all sites. The programs were highly rated. Student ratings, scores, and behaviors were independent of institution and mode of use. CONCLUSION: A multicenter educational consortium developed a system to produce unique, sophisticated MCAI programs in cardiology. Both system and programs functioned reliably at four institutions and were highly rated by fourth-year medical students. With this enthusiastic reception, the economies and strengths associated with MCAI make it an attractive solution to a number of problem areas, and it will likely play an increasingly important role.

Digital embolization from plaque-related thrombus in the thoracic aorta: identification with transesophageal echocardiography and resolution with warfarin therapy.

A 71-year-old man had painful blue toes after an episode of protracted vomiting. Abdominal, cardiac, and transesophageal ultrasound studies were performed before angiography was considered. A large mobile mass in the proximal descending thoracic aorta, which suggested thrombus, was identified by transesophageal echocardiography. With no further evaluation, anticoagulant therapy with heparin and warfarin was initiated. Three months later, repeated transesophageal echocardiography demonstrated only a tiny vestige of the plaque-related mass. The pain and discoloration of the toes resolved completely. The advantages and disadvantages of the various diagnostic and therapeutic approaches to peripheral embolization are discussed.

Beat-by-beat aortic valve area measurements indicate constant orifice area in aortic stenosis: analysis of Doppler data with varying RR intervals.

Gorlin formula calculation of aortic valve area suggests that orifice area increases in patients with aortic stenosis with rising cardiac output. Evidence that aortic orifice area varies was sought in patients with aortic stenosis by analyzing Doppler data beat by beat versus RR interval in 22 patients with spontaneous RR variability. Stroke volume increased in all patients from minimum to maximum RR interval by 129% +/- 19%. Over the same range of RR intervals, assessment of aortic valve area by (A) simultaneous inner and outer continuous wave Doppler signals, or (B) nonsimultaneous RR-matched pulsed wave Doppler from the left ventricular outflow tract and continuous wave Doppler from the aortic valve failed to suggest an increase in aortic valve area. A positive relationship between aortic valve area and RR interval was not consistently observed with the exception of seven out of eight patients with mild to moderate (pulsed wave Doppler/continuous wave Doppler time velocity integral ratio of 0.3 to 0.7) aortic stenosis (p less than 0.05). Beat-by-beat measurements of aortic valve orifice area using Doppler techniques do not suggest that the aortic stenosis orifice varies over a wide range of RR intervals and stroke volumes.

Unruptured noncoronary sinus of Valsalva aneurysm: preoperative characterization by transesophageal echocardiography.

We describe a patient with a large unruptured sinus of Valsalva aneurysm that was discovered incidentally. Transesophageal echocardiography was used to characterize the aneurysm preoperatively, and was helpful intraoperatively in assessment of the degree of native aortic valvular regurgitation after repair. The use of transthoracic echocardiography, contrast echocardiography, Doppler echocardiography, and transesophageal echocardiography are discussed in this condition.

How much testing is needed after myocardial infarction?

Both physicians and patients should be encouraged by the tremendous progress made in the clinical care of patients with heart disease during the last 20 years. However, the number of invasive and noninvasive tests is vast, so they need to be applied judiciously, using a reasonable set of clinical principles to recognize the needs of the individual patient. In the case of myocardial infarction, one of the most important prognostic factors is left ventricular systolic function, which is commonly measured by the ejection fraction. This measurement can be made with a left ventriculogram, radionuclide ventriculogram, or two-dimensional echocardiogram, the choice depending on individual circumstances.

Clinical utility of transesophageal echocardiography.

Routine transthoracic echocardiography fails to generate images of diagnostic quality in a significant number of patients who are obese, uncooperative, or unable to be properly positioned (eg, patients receiving ventilatory assistance), and in those with severe chronic obstructive pulmonary disease, chest wall deformities, or recent thoracic surgical procedures. In addition, posterior structures in the heart such as the left atrium, left atrial appendage, atrial septum, and mitral valve are seen with poorer resolution than structures closer to the anterior chest wall. Placement of a sonographic transducer in the esophagus immediately behind the heart circumvents these limitations. Newly developed probes are well tolerated by sedated conscious patients as well as by patients receiving ventilatory assistance in the intensive care unit and those under general anesthesia. Consequently, transesophageal echocardiography is now available for further enhancement of cardiac diagnosis in outpatients, for evaluating the hemodynamic status of critically ill patients in the intensive care unit, for intraoperative assessment of cardiac repairs, and for intraoperative cardiac monitoring in noncardiac surgical procedures. A series of case examples from our practice during a recent 1-year period illustrates the clinical utility of this technique in these settings.

Right-to-left shunt across a patent foramen ovale caused by cardiac tamponade: diagnosis by transesophageal echocardiography.

Cardiac tamponade can manifest as profound hypoxemia from intracardiac shunting across a patent foramen ovale. As a consequence, pulmonary embolus can be erroneously diagnosed. As demonstrated in the case described herein, transesophageal echocardiography can be useful in determining the correct diagnosis, especially if transthoracic echocardiography is technically limited. In our patient, the findings on transesophageal echocardiography also helped determine the appropriate treatment. The relative inaccessibility of the pericardial effusion to needle drainage prompted open surgical drainage.

Tricuspid valve papillary fibroelastoma: echocardiographic characterization.

We report a tricuspid valve papillary fibroelastoma initially detected by transthoracic two-dimensional echocardiography and subsequently characterized by transesophageal two-dimensional echocardiography. The mass was excised during open heart operation, and the diagnosis was verified grossly and histopathologically. Transesophageal echocardiography usually provides images far superior to those from transthoracic echocardiography and may be a useful adjunct for intraoperative localization of intracardiac tumors for excision.

Aortic dissection: review of value and limitations of two-dimensional echocardiography in a six-year experience.

The utility of transthoracic two-dimensional echocardiography in patients with aortic dissection was assessed by retrospective analysis in 67 patients: 31 patients with DeBakey type I, 21 patients with type II, 10 patients with type III, and five patients with false-positive diagnoses. Aortic dissection was correctly identified by two-dimensional echocardiography in 49 patients; 13 had false-negative diagnoses. Therefore the sensitivity was 79%, and the positive predictive accuracy was 91%. Transthoracic two-dimensional echocardiography is a reasonable screening technique for diagnosis of aortic dissection.