Cardiac arrhythmias. Frequency during fiberoptic bronchoscopy and correlation with hypoxemia.

To evaluate the occurrence of ECG abnormalities during fiberoptic bronchoscopy in relation to specific stages of the procedure and to hypoxemia, we prospectively studied 50 hospitalized patients aged 53 +/- 18 years (mean +/- SD) who were undergoing bronchoscopy by continuously monitoring cardiac rhythm with a continuous two-channel ECG recorder and oxygen saturation by using ear oximetry. Major disturbances of cardiac rhythm (ie, atrial, ventricular, or both) developed in 20 (40%) patients. Ventricular arrhythmias were recorded in ten patients (20%) and occurred with greatest frequency during passage of the bronchoscope through the vocal cords in five of these patients. Atrial arrhythmias were detected in 16 patients (32%), but their occurrence did not correlate closely with any one stage of the procedure. Arrhythmias were most frequent in association with periods of maximum oxygen desaturation in 12 of these 20 patients. Oxygen desaturation persisted for greater than one hour after bronchoscopy in 34 (68%) of 50 subjects. Notably, no correlation was observed between the frequency of arrhythmias during bronchoscopy and patients' age, sex, prior medications, or preexisting cardiac or pulmonary disorders. In no case was an ECG abnormality associated with adverse clinical sequelae.

Pleural effusion as the initial manifestation of disseminated cryptococcosis in acquired immune deficiency syndrome. Diagnosis by pleural biopsy.

Pleural effusion is an unusual presentation of cryptococcal infection in the acquired immune deficiency syndrome. Previous investigators have established the diagnosis of cryptococcal pleural disease by culturing pleural fluid, bronchial washings, and extrapulmonary sources. We report the first case of cryptococcal pleural effusion proved by closed pleural biopsy. Pleural biopsy may be an effective and rapid method of determining the etiology of pleural effusion in the acquired immune deficiency syndrome.

Prognosis of pulmonary scar carcinoma.

Eighty-one patients with resectable primary peripheral lung carcinomas were studied to determine the effect of associated scarring on prognosis. Twelve tumors (15%) originated from bronchi. 24 (30%) were associated with scars, and 45 (55%) were not associated with either bronchus or scar (non-scar). Scar carcinomas differed significantly in cell type from bronchogenic and non-scar tumors in that 21 (88%) scar carcinomas were either adenocarcinomas or bronchioloalveolar carcinomas (p less than 0.001). Origin (bronchogenic, scar, non-scar) independent of cell type and tumor stage did not significantly influence survival. Stage of disease independent of cell type or origin affected survival (p less than 0.0001), as did cell type independent of tumor stage or origin (p less than 0.0001). Stage I disease and bronchioloalveolar carcinoma were associated with longer survival, while Stage II or III disease, small cell anaplastic carcinoma, and adenocarcinoma were associated with reduced survival. We conclude that associated scar influences cell type of peripheral lung carcinoma but does not influence patient survival, even among patients with similar cell type and stage of disease.

Pseudotumor of kidney.

Hypertrophy of the renal columns of Bertin may present as a mass, at times difficult to distinguish from neoplasia or cyst. Herein, we present a case characterized by the inability of this lesion to absorb 99mTc DTPA (99mTechnetium diethylenetriaminepentaacetic acid) isotope on two separate renal studies.

Isolated right ventricular infarction complicated by ventricular septal defect.

Right ventricular infarction is frequently seen with inferior myocardial infarction, but it rarely presents in isolation. We describe a case of isolated right ventricular infarction complicated with ventricular septal defect. Clinical, hemodynamic, echocardiographic, and surgical features are discussed. Twenty months following surgical repair of the ventricular septal defect and two vessel coronary artery bypass surgery, the patient continues to do well and is free from angina and exertional dyspnea.

'Abnormal' diastolic Doppler patterns in patients over age 65 with severe left ventricular systolic dysfunction.

OBJECTIVE: The purpose of this study was to determine whether Doppler diastolic filling patterns of the left ventricle are altered in patients over age 65 with poor left ventricular function, compared to patients with normal left ventricular systolic function. BACKGROUND: In elderly, healthy subjects, the mitral valve Doppler inflow pattern exhibits an increase in atrial contribution to left ventricular filling. Myocardial disease, which results in stiffness, may also cause an increase in A wave velocity. METHODS: Twenty-seven patients over age 65, with left ventricular systolic dysfunction, were age and sex-matched with 19 patients with normal left ventricular systolic function. Patients with significant mitral or aortic valvular disease were excluded. Maximal early inflow velocity, maximal atrial inflow velocity, heart rate, acceleration time and deceleration time were calculated. RESULTS: Comparing the group with normal left ventricular systolic function, the group with decreased left ventricular systolic function had pseudonormalization of the maximal early flow/atrial flow velocity ratio (1.7 +/- 1.3 vs. 0.9 +/- 0.3; P = 0.003), E wave velocity was similar (82 +/- 28 vs. 70 +/- 24 cm/s; P = n.s.), and A wave velocity was diminished (66 +/- 30 vs. 84 +/- 20 cm/s; P = 0.02). The acceleration time was similar for the groups (53 +/- 17 vs. 46 +/- 21 ms), but the deceleration time was shorter in patients with left ventricular systolic dysfunction (122 +/- 33 vs. 192 +/- 80 ms; P < 0.001). CONCLUSION: Such differences may relate to increased left atrial pressure, increased left ventricular diastolic pressure and/or decreased atrial systolic function. These findings are important when interpreting left ventricular filling indices by Doppler echocardiography in elderly patients.

Censored lifetime data in adaptive neural networks.

BACKGROUND AND AIM OF THE STUDY: In clinical research, survival, reliability and failure analyses, the use of censored lifetime data often becomes a necessity. In this paper we present a novel methodology developed to allow for the use of censored data to train neural networks to predict the time of specific adverse events. METHODS AND RESULTS: Specifically, for patients with implanted bioprostheses, we were able to design and train a neural system to successfully predict the time from valve implant to valve dysfunction. Further, we were able to demonstrate the clear improvement in performance and predictive accuracy of the system when trained using this method. The assertion that censored data carry additional and extremely valuable information, especially in cases of rare events, is substantiated by this correlation analysis. CONCLUSIONS: This new methodology, in combination with results obtained from previous models which were able to identify the patients most likely to experience such events, now completes the picture by pin-pointing the 'who', as well as the 'when'.

Neural net-bootstrap hybrid methods for prediction of complications in patients implanted with artificial heart valves.

A novel hybrid methodology for prediction of valve related complications in patients with implanted artificial heart valves is discussed. Artificial neural networks provided a mechanism for prediction of postoperative valve-related deaths based on preoperative patient information and valve parameters. Then bootstrap methodology was applied for estimating prediction errors and maximizing prediction accuracy. Data from a clinical trial with 10 years of follow-up on 789 patients implanted with Carpentier-Edwards Pericardial Bioprosthesis were used. A random subset of the data was reserved for validation of the final outcome. The remaining patients' records were repeatedly divided into two groups, using resampling strategy provided by the bootstrap methodology. One of the groups was used for training the neural net and the other one for testing the trained network and determining error rates. Patient information, such as sex, age, NYHA class and anticoagulation therapy, as well as valve parameters, such as size and the date of implant were used as the network inputs. Calculated error rates were then used for assessing the distribution of the error, further optimization of the neural network, and constructing confidence intervals for the error rates. Thus, reliable statistical estimation was obtained on the prediction accuracy. Additionally this new hybrid methodology allowed us to optimize the neural network even further, raising the accuracy of prediction to 78%.

Prediction of valve-related complications for artificial heart valves using adaptive neural networks: a preliminary study.

A novel approach to the prediction of valve-related complications in patients with implanted artificial heart valves is discussed. Adaptive artificial neural networks were used to identify patients at high risk of valve-related events based on preoperative data. Data from a clinical trial on 789 subjects with Carpentier-Edwards pericardial bioprostheses were used. Patients' records were divided into two groups, one of which was used for training the neural network and the other for testing the trained network and determining error rates. Patient information such as age, sex, NYHA class and anticoagulation therapy, as well as valve information such as size and the date of implant, were used as the network inputs. The neural net had a single output variable indicating the risk that an individual patient would develop a valve-related complication resulting in death. The results show that a trained neural network was able to predict valve-related deaths in the specified time interval of 1981-1991 with a high degree of accuracy. The neural network was also successful in classifying patients into high and low risk categories.

Long-term durability and patient functional status of the Carpentier-Edwards Perimount pericardial bioprosthesis in the aortic position.

BACKGROUND AND AIMS OF THE STUDY: The study aim was to examine the long-term durability of the aortic Carpentier-Edwards Perimount pericardial bioprosthesis using actuarial and actual analyses. METHODS: A total of 267 patients were implanted at four centers between September 1981 and December 1983. Of these patients, 171 (64%) were males and 96 (36%) females; mean age at implant was 64.9+/-11.8 years (range: 21 to 86 years). Patients have been followed for 9.1+/-4.2 years (total 2335.7 patient-years). Long-term echocardiography data are presented. RESULTS: The total operative (<30 days postoperative) mortality rate was 4.9%; of this, 0.4% was valve-related. The total late (> or = 30 days postoperative) mortality rate was 6.2%/pt-yr and included a valve-related mortality rate of 1.6%/pt-yr. Complications of thromboembolism, thrombosis and bleeding showed linearized rates of 1.6%/pt-yr and 0.4%/pt-yr, respectively. Valve dysfunction resulted in an explant rate of 0.9%/pt-yr and an associated mortality rate of 0.1%/pt-yr. At 14 years post implant, actuarial freedom from overall and valve-related death was 39.3% and 78.8%, respectively. Actuarial and actual freedom from valve dysfunction was 70.4% and 81.7%. Actuarial freedom from valve explant as a result of dysfunction was 85.1% in all patients; explant in patients aged < or = 65 years at implant was less (76.1%) than in patients aged >65 years (96.3%). CONCLUSION: The high actuarial and actual freedom from explant due to structural valve dysfunction supports the long-term durability of this pericardial bioprosthesis and justifies its clinical use in patients older than 65 years at implant.

The value and promise of echocardiography in acute myocardial infarction and coronary artery disease.

Two-dimensional and Doppler echocardiography have become extremely useful in the management of patients with acute myocardial infarction (AMI). Echocardiography is noninvasive, relatively inexpensive, and has no known biohazards. It offers unequaled information about cardiac anatomy and function. In the acute setting it is useful in the diagnosis of AMI and its complications. It is an excellent tool for monitoring therapy. Echocardiography has been shown to be useful in risk stratification upon presentation to the emergency ward and prior to hospital discharge. Stress echocardiography has broadened and sharpened the diagnostic and prognostic information. Contrast echocardiography has promise for demonstrating coronary artery flow. Research in ultrasonic myocardial tissue characterization shows potential for differentiating ischemic myocardium from infarcted myocardium. Thus, echocardiography is likely to become increasingly important in the future management of patients with AMI.

Pitfalls in the diagnosis and management of papillary muscle rupture: a study of four cases and review of the literature.

Four cases of papillary muscle rupture occurring in the setting of acute myocardial infarction are presented, which illustrate the following points: the diagnosis may not be apparent at presentation, a mitral regurgitant murmur may be absent, transesophageal echocardiography may establish the diagnosis when transthoracic echocardiography does not, and appropriate surgical correction can lead to excellent functional recovery.

Acanthosis nigricans in obese patients: Presentations and implications for prevention of atherosclerotic vascular disease.

Acanthosis nigricans is traditionally characterized by hyperpigmented, velvety plaques of body folds. Involvement of other areas occurs as well. The condition is caused by hyperinsulinemia, a consequence of insulin resistance that occurs associated with obesity. As the frequency and degree of obesity increase in the population, a concomitant increase in acanthosis nigricans can be expected. The dermatologist has an important role in identifying the subset of obese patients with acanthosis nigricans. These patients have hyperinsulinemia and may be at greater risk of consequent atherosclerotic cardiovascular disease. It is essential for dermatologists to recognize the many presentations of acanthosis nigricans to identify patients at risk for associated medical conditions. This article illustrates a variety of presentations of acanthosis nigricans associated with insulin resistance.

Timing of surgery in chronic aortic regurgitation.

When deciding on therapy for aortic regurgitation (AR), it is imperative to distinguish between acute and chronic AR. Symptoms and echocardiographic findings are essential in distinguishing acute from chronic AR and in assessing the severity. Vasodilators have been shown to be helpful in treating patients with chronic severe AR. The timing of aortic valve replacement in chronic severe AR remains controversial. Symptoms, left ventricular function, and response to exercise have been shown to be the most important prognostic indicators.

Multimedia image display: a view to the future.

The development of multimedia image review stations offers the cardiologist the ability to review multiple image sets in a single setting rather than moving from one review station to another. To accomplish this goal there are three essential barriers: 1) memory requirements for digital images; 2) standardization of data format; and 3) practical user interfaces. Image compression algorithms can be used to overcome the digital barrier; however, these must be used cautiously so as to not adversely affect image quality. The lack of standardization is being addressed by the implementation of the Digital Communication in Medicine (DICOM) standard, and practical user interfaces are being developed every day with the widespread implementation of World Wide Web technology. These solutions will allow the clinician to review all of a patient's image data in one location, such as in the office, on the nursing unit, or at home.

Facial dermatitis: patch test results and final diagnoses.

BACKGROUND: Facial dermatitis may result from allergic or irritant contact dermatitis, from endogenous conditions such as atopic or seborrheic dermatitis, or a combination of contributing factors. OBJECTIVE: To determine the final diagnoses in patients referred for evaluation of facial dermatitis, and the relevant allergens in those ultimately diagnosed with allergic contact dermatitis (ACD). METHODS: A retrospective chart analysis of all patients patch tested for evaluation of facial dermatitis in an Occupational and Contact Dermatitis referral clinic over a 2-year period from October 1995 to October 1997. RESULTS: Of the 383 patients patch tested, 85 (22%) had facial dermatitis. Of these 85 patients, 55 (65%) had spotty or diffuse facial involvement, 21 (25%) had only eyelid involvement, and in 9 (10%) only the lips were involved. Final diagnoses were relatively equally distributed among three categories: one third had ACD, one third had ACD with other contributing factors, and one third had diagnoses other than ACD. Among patients with ACD, the most common relevant allergens were personal care products, preservatives, and fragrances. CONCLUSION: Allergic contact dermatitis is a frequent cause of facial dermatitis in a referral dermatology clinic. However, in up to two thirds of patients, other diagnoses represent either the primary process or a major component contributing to the eruption. Personal care products, preservatives, and fragrances represent the most common relevant allergens in those diagnosed with ACD. A significant number of relevant reactions would be missed if only the TRUE test standard series were used.