Pericardial mesothelioma masquerading as a benign pericardial effusion.

A 53 year old asymptomatic man presented with a primary pericardial mesothelioma masquerading as a benign pericardial effusion. Although M-mode echocardiography showed an echo-free space, two-dimensional echocardiography and thoracic computed tomography demonstrated that the suspected effusion was caused by a mass surrounding the heart. Newer noninvasive techniques can be valuable for the early detection of pericardial tumor.

Doppler echocardiographic analysis of left ventricular filling in treated hypertensive patients.

Early detection and prevention of cardiac dysfunction is an important goal in the management of hypertensive patients. In this study, Doppler echocardiography was used to evaluate the pattern of left ventricular diastolic filling in 38 subjects: 18 treated hypertensive patients (blood pressure 141 +/- 17/83 +/- 10 mm Hg, mean +/- SD) without other coronary risk factors and 20 risk-free normotensive subjects of similar age (47 +/- 10 and 49 +/- 13 years, respectively). Peak velocity of late left ventricular filling due to the atrial contraction was greater in hypertensive compared with normotensive subjects (69 +/- 14 versus 52 +/- 13 cm/s; p less than 0.001). Peak velocity of late filling was significantly greater in hypertensive versus normotensive subjects in those aged 50 years or younger and those older than age 50 (65 +/- 12 versus 50 +/- 11; p less than 0.01 and 75 +/- 15 versus 56 +/- 15 cm/s; p less than 0.05, respectively). In hypertensive subjects, peak velocity of late filling did not correlate with routine indexes of hypertensive heart disease (including posterior wall thickness and left ventricular mass), systolic and diastolic blood pressure or duration of hypertension. These results indicate that increased velocity of late left ventricular filling may be independent of left ventricular hypertrophy and persist despite effective blood pressure control.

Carotid sinus hypersensitivity. Case report and review of the literature.

Carotid sinus hypersensitivity is a potentially treatable cause of recurrent neurologic symptoms. Diagnosis depends upon recognizing the variable presentation of symptomatic carotid sinus hypersensitivity, and noting an exaggerated cardiovascular response to carotid sinus massage associated with neurologic symptoms. Once the diagnosis of symptomatic carotid sinus hypersensitivity has been established, it is important to delineate the type of hypersensitivity present, because identification of the vasodepressor response has important therapeutic implications.

Using exercise respiratory measurements to compare methods of exercise prescription.

Exercise heart rate (HR) ranges based on peak HR, age-predicted maximal HR and peak oxygen consumption were compared to determine which method is most likely to result in an exercise prescription within guidelines determined from exercise respiratory measurements (upper limit--ventilatory threshold; lower limit--50% peak oxygen consumption). Exercise prescriptions based on either 80% peak HR or 70% peak measured oxygen consumption were significantly more likely to be within these guidelines (p less than 0.05) than other criteria tested; there was no significant difference between these 2 methods. Recommended exercise intensity based on 85% peak HR and 80% peak oxygen uptake resulted in a large percentage of patients with a heart rate above the ventilatory threshold (46% and 54%, respectively), whereas target HR derived from 75% peak HR and 60% peak oxygen consumption resulted in many patients with a heart rate below the lower limit (38% and 42%, respectively). Exercise prescription based on predicted maximal HR was of little value, regardless of the percentage used to determine target heart rate. The best methods identified in this study yielded an exercise intensity exceeding ventilatory threshold 15 to 20% of the time. Exercise prescription based on direct assessment of the ventilatory threshold is therefore preferred.

Sudden cardiac death one hour after a negative exercise test. Coronary angiographic follow-up.

A 58-year-old man developed ventricular fibrillation and a large anterior infarction one hour after a negative exercise test. Coronary angiography post-infarction suggested the presence of a "complicated" lesion, raising the possibility that the infarction resulted from sudden occlusion of a previously nonsignificant lesion.

Unilateral neck pulsations in a patient with a permanent pacemaker.

An asymptomatic patient with a permanent pacemaker presented with unilateral accentuated neck pulsations. Evaluation revealed tricuspid insufficiency, a massively dilated right internal jugular vein, and obstruction of the left internal jugular vein. There was no evidence of aneurysm, vascular tumor, or fistula. The most likely explanation for this constellation of findings is tricuspid regurgitation occurring in the setting of unilateral internal jugular vein occlusion. Such a combination should be considered in the differential diagnosis of asymmetrical neck pulsations in a patient with a transvenous pacemaker.

Ostial left main stenosis following repair of a ruptured sinus of Valsalva aneurysm.

A patient complained of angina pectoris nine months after surgical repair of an aortic right atrial fistula and mitral valve replacement. Subsequently, he was shown to have a new obstruction of the ostium of the left main coronary artery. This case illustrates the need to consider this syndrome in the differential diagnosis of postoperative complaints of chest pain, especially following an operation which involves direct cannulation of the coronary arteries.

Hemodynamic compromise secondary to a mediastinal bronchogenic cyst.

Bronchogenic cysts are not commonly the cause of severe symptoms, and often present only as an abnormality on chest roentgenogram. We report an unusual patient with a mediastinal bronchogenic cyst associated with rapid hemodynamic deterioration secondary to compression of vital structures.

Exercise-related atrioventricular block. Influence of myocardial ischemia.

A 62-year-old woman was noted to have complete heart block immediately following an exercise stress test. Coronary arteriography subsequently revealed a significant lesion in the right coronary artery, which was successfully dilated. Thallium-exercise testing following angioplasty showed no evidence of inducible ischemia and no arrhythmia was seen, supporting the idea that exercise-related heart block may occur secondary to myocardial ischemia.

Resting diastolic function and left ventricular mass are related to exercise capacity in hypertensive men but not in women.

We evaluated the impact of diastolic function and gender on exercise capacity in sedentary, untreated hypertensive subjects (34 men, 23 women) using echocardiography and a bicycle ergometry with measurement of oxygen consumption (VO2). In men, peak (A) mitral inflow velocity and left ventricular (LV) mass were inversely related to peak VO2 (r = -0.64) and maximal workload (r = -0.57) and were the sole independent determinants of exercise capacity. In women, there was no relationship between any echocardiographic measure and exercise capacity. Thus, LV mass and Doppler-determined diastolic function predict maximal VO2 in hypertensive men but not in women. This finding may be related to gender differences in the contribution of diastolic filling to exercise capacity or may reflect limitations of resting Doppler echocardiography to predict exercise diastolic filling in hypertensive women.

Comparison of two calcium blockers on hemodynamics, left ventricular mass, and coronary vasodilatory in advanced hypertension.

Dihydropyridine and nondihydropyridine calcium channel blockers (CCB) differ in pharmacologic characteristics. Few clinical studies distinguish effects of CCB as monotherapy. We conducted a comprehensive comparison of two CCB on patients with moderate to severe hypertension. Thirty patients with pretreatment diastolic blood pressures > or = 100 mm Hg were randomly assigned to either nifedipine-GITS or verapamil-SR. Dose titration achieved a diastolic blood pressure of < or = 95 mm Hg or a decrease of > or = 15 mm Hg over 4 weeks. Clinic blood pressure (BP), 24-h ambulatory BP, exercise BP, left ventricular mass, systolic and diastolic function by echocardiography, and coronary flow reserve by split-dose thallium-201 imaging with adenosine were assessed at baseline, end of titration, 3 months and 6 months of treatment. Plasma renin activity, atrial natriuretic peptide, norepinephrine, and epinephrine were assayed. Both drugs caused similar reductions in clinic and 24-h ambulatory BP and similar reductions in left ventricular mass index. Compared to nifedipine-GITS, verapamil-SR produced a significantly lower resting and peak exercise heart rate. Nifedipine-GITS elicited a lower peak exercise systolic BP. At end titration nifedipine-GITS produced lower plasma atrial natriuretic peptide levels, no longer apparent by 6 months. Plasma norepinephrine was lower with verapamil-SR, also at end titration and at 3 months, but not at 6 months. Plasma epinephrine and plasma renin activity were unchanged by either drug. There was no difference for systolic or diastolic left ventricular function or coronary flow reserve between the two treatments. Once daily nifedipine-GITS and verapamil-SR are equally effective for reduction of arterial pressure in moderate to severe hypertension. Differences in their hemodynamic profiles and neurohormonal responses are consistent with preclinical pharmacologic characteristics. The clinical implications of their similarities and differences remain to be fully evaluated in outcome studies.

Naloxone-responsive hypotension in a patient with an ACTH-secreting tumor.

We report a case in which hypotension was corrected by the administration of naloxone in a patient with an ACTH-secreting mediastinal tumor. According to previous reports, reversal of hypotension would not be expected in patients with suppressed central ACTH secretion. The implications of this patient's response on the possible mechanisms for naloxone's action in reversing septic shock are discussed.

Effects of fire fighting uniform (modern, modified modern, and traditional) design changes on exercise duration in New York City Firefighters.

Fire departments have replaced traditional uniforms with modern, more thermal protective gear. Although the new uniforms afford superior burn protection, they may reduce work time. Our purpose was to determine if exercise time was (1) reduced by wearing the modern versus traditional uniform, and (2) increased by a design change to a modified modern uniform (T-shirt and short pants rather than a shirt and long pants under the outer uniform). Male firefighters (n = 23; age 27 to 59) performed a maximum exercise test in gym clothes (maximal oxygen consumption = 46 +/- 9 ml/kg/min) and then returned on separate days to exercise using a moderately high intensity, constant work rate treadmill protocol while wearing fire fighting breathing apparatus and each of three uniforms. Firefighters exceeded anaerobic threshold by 1 minute and eventually reached or exceeded maximum heart rate and maximal oxygen consumption. Exercise time in modern (15 +/- 3 min) was significantly less than in traditional (18 +/- 5 min) uniform. Exercise time in modified modern (17 +/- 5 min) was significantly greater than in modern and not significantly different than in traditional uniforms. The rate of change in oxygen consumption and water loss were significantly affected by uniform type, with faster rates in modern compared with modified modern or traditional uniforms. These findings show the impact that design changes have on energy demands and exercise duration.

Comparison of arm and treadmill exercise at 85% predicted maximum heart rate.

Both treadmill exercise and arm exercise are used for evaluating coronary artery disease, but arm exercise has lower diagnostic sensitivity. We compared the two exercise modalities with respect to the rate-pressure product at 85% predicted maximal heart rate, a parameter frequently used to denote performance of sufficient exercise to derive clinical conclusions. At this heart rate, treadmill exercise resulted in a significantly greater systemic oxygen consumption (2.7 +/- .8 vs. 2.1 +/- .6 l/min) and rate-pressure product (30.6 +/- 4.4 X 10(3) vs. 28 +/- 3.3 X 10(3)) than arm ergometry. An inability to generate sufficient imbalance of myocardial oxygen supply and demand may account for the relatively higher incidence of false negative exercise tests seen with arm ergometry, especially if the exercise test is stopped when the patient attains 85% predicted maximal heart rate.

Mechanism underlying the absence of ischemic changes on the exercise electrocardiogram in patients with abnormal exercise thallium-201 imaging and coronary artery disease.

Patients with coronary artery disease may have reversible abnormalities on a thallium myocardial perfusion study without simultaneous ischemic changes on the exercise electrocardiogram, but the mechanisms responsible for this disparity have not been fully elucidated. A group of 37 patients with angiographically demonstrated coronary artery disease and abnormal thallium perfusion imaging were divided into two groups on the basis of their exercise electrocardiographic ST segment response. Thirteen patients (Group A) had no significant electrocardiographic changes with exercise, while 24 patients (Group B) had ST changes consistent with ischemia during the test. There were no significant differences in clinical or angiographic characteristics between the two groups. Stress test results showed a similar mean duration of exercise in the two groups (6.2 +/- 1.8 versus 6.7 +/- 2.5 min, p = NS), but the patients in Group A achieved a significantly lower mean maximal heart rate (117 +/- 26 versus 132 +/- 21 beats/min, p less than 0.05) and mean maximal double product (19,650 +/- 5116 versus 22,650 +/- 4871, p less than 0.05). There was no consistent pattern of thallium perfusion abnormality noted in Group A to suggest that a particular region of electrically silent myocardium was responsible for ischemia in the absence of electrocardiographic changes. These results suggest that exercise thallium-electrocardiogram discordance is mediated by the level of myocardial workload achieved. An abnormal perfusion scan accompanying an exercise electrocardiogram which does not demonstrate any ischemic ST change may occur when there is sufficient increase in myocardial oxygen demand to result in differential augmentation of myocardial blood flow, but insufficient imbalance of supply and demand to result in signs of ischemia on the surface electrocardiogram.

Ventricular Tachycardia in a Marathoner.

In brief Young marathoners who run 60 miles per week may appear to be in great shape. But episodes of palpitations and light-headedness may signify a cardiovascular problem. Tests can reveal just how deceiving appearances can be.