Incidence of left atrial thrombi in patients in sinus rhythm and with a recent neurologic deficit.

OBJECTIVES: We sought to determine the incidence of left atrial (LA) thrombi in patients in sinus rhythm (SR) and with a recent neurologic deficit and to analyze the relation between LA thrombi and LA chamber and appendage function in patients in SR. METHODS: A prospective study was conducted in 869 consecutive patients. The study group consisted of 583 patients in SR (67%). The remaining 286 patients had atrial fibrillation (AF) and served as controls (33%). RESULTS: The incidence of LA thrombi was significantly higher in patients with AF (n = 39 [14%]) compared with patients in SR (n = 6 [1%]; P <.001). Three of 6 patients with thrombi in SR had mitral stenosis, 1 patient had aortic stenosis, 1 patient had coronary artery disease, and another patient had a cardiomyopathy. Of the patients with detected thrombi, those in SR did not receive anticoagulation, whereas those with AF did in 18 cases. Patients with thrombi in SR and with AF did not significantly differ in LA diameter (5.1 +/- 0.8 cm vs 4.8 +/- 0.7 cm; 95% confidence interval [CI], -0.78 to 0.45), left ventricular ejection fraction (46% +/- 13% vs 42% +/- 15%; 95% CI, -18.7 to 7.4), LA appendage area (5.8 +/- 2.7 cm(2) vs 6.7 +/- 3.2 cm(2); 95% CI, -1.9 to 3.6), peak emptying velocity of the LA appendage (0.19 +/- 0.08 m/s vs 0.17 +/- 0.07 m/s; 95% CI, -0.08 to 0.04), or LA spontaneous echo contrast (3. 5 +/- 0.6 vs 3.9 +/- 0.5; 95% CI, -0.06 to 0.45). CONCLUSIONS: LA appendage thrombi are an infrequent cause of thromboembolism in patients in SR and are associated either with mitral valve disease or LA chamber and appendage dysfunction. Routine transesophageal echocardiography for the exclusion of LA thrombi is not recommended in patients in SR without underlying heart disease and normal LA function as assessed by transthoracic echocardiography.

Effects of allopurinol, propranolol and methylprednisolone on infarct size in experimental myocardial infarction.

With use of a canine model of occlusion of the left anterior descending coronary artery and an intracellular lactic dehydrogenase stain to measure infarct size directly, the effects of allopurinol, methylprednisolone sodium succinate and propranolol were studied. Allopurinol did not influence the extent of myocardial necrosis, whereas both methylprednisolone and propranolol significantly reduced myocardial infarct size. Possible mechanisms of action and clinical applicability of these agents are discussed.

Heart rate to work rate relation throughout peak exercise in normal subjects as a guideline for rate-adaptive pacemaker programming.

We investigated the physiologic heart rate (HR) to work rate (WR) relation throughout peak exercise in normal subjects as a guideline for rate-adaptive pacemaker slope programming. The study group consisted of 41 middle-aged subjects (22 men and 19 women) without evidence of cardiopulmonary disease. Peak-exercise stress tests were performed on a calibrated treadmill by using the symptom-limited "ramping incremental treadmill exercise" (RITE) protocol. The HR response, oxygen uptake, and treadmill workload increments were assessed simultaneously. The HR/WR slope, as determined using linear regression analysis, was 0.37 +/- 0.13 beats/min/W for the entire study group, which indicates an upper range increase of 5 beats/10 W increase of external treadmill work performed, using the mean value +/- 1 SD. Men generated an HR/WR slope of 0.32 +/- 0.09 beats/min/W, and women, 0.43 +/- 0.15 beats/min/W, indicating a significant sex-related difference in the HR/WR relation (p < 0.01). Thus, to achieve an appropriate matching of HR with patient effort, rate-adaptive pacemakers should generate an average increase of approximately 5 beats per increase in 10 W of external treadmill work. The HR/WR relation can easily be determined to provide the clinician with a minimal check system to avoid a hyper- or hypochronotropic paced response to exercise.

Echocardiographic parameters for predicting maintenance of sinus rhythm after internal atrial defibrillation.

Chronic atrial fibrillation (AF), which is refractory to external electrical direct current shock and/or pharmacologic cardioversion, may be successfully cardioverted using internal atrial defibrillation. To avoid unnecessary procedures, it is important to be able to predict which patients will revert to AF. Thirty-eight patients with chronic AF underwent successful internal atrial defibrillation and were followed for 6 months after restoration of sinus rhythm. Left atrial (LA) diameter, left ventricular ejection fraction, maximum LA appendage area, and peak emptying velocities of the LA appendage were analyzed to determine which of these factors were associated with recurrence of AF. Forty-nine percent of patients had a recurrence of AF within 6 months following internal atrial defibrillation. The preprocedural ejection fraction (mean +/- SD 59 + 14% vs 57 + 13%, p = 0.63), LA diameter (4.2 +/- 0.6 cm vs 4.5 +/- 0.6 cm, p = 0.16), and LA appendage area (5.0 +/- 1.5 cm2 vs 5.8 +/- 1.5 cm2, p = 0.13) did not differ significantly between patients who maintained sinus rhythm and those who had recurrence of AF. Peak emptying velocities of the LA appendage before cardioversion were significantly lower in patients with recurrence of AF compared with patients who maintained sinus rhythm (0.26 +/- 0.1 m/s vs 0.49 +/- 0.17 m/s, p = 0.001). A peak emptying velocity <0.36 had a sensitivity of 82% and a specificity of 83% for predicting recurrence of AF.

Hemodynamic and cardiorespiratory function following internal atrial defibrillation for chronic atrial fibrillation.

Internal atrial defibrillation (IAD) is able to restore sinus rhythm in patients with chronic atrial fibrillation (AF) and failed external electrical and/or pharmacologic cardioversion. To assess whether cardiorespiratory and hemodynamic function improve after IAD, 35 patients were prospectively investigated during constant workload exercise by spiroergometry and Doppler echocardiography before IAD, and 1 day and 1 month after IAD. Oxygen uptake kinetics, ventilation, left atrial mechanical function, and pulmonary artery pressure were determined simultaneously at rest and during steady state. During the serial follow-up, 20 patients maintained sinus rhythm. The time interval for achieving the steady state (146 +/- 53 vs 132 +/- 42 seconds; p = 0.5) and the oxygen deficit (645 +/- 190 vs 670 +/- 174 ml; p = 0.7) were not different before and 1 day after IAD, but decreased significantly after 1 month (98 +/- 16 seconds, p = 0.01 and 487 +/- 72 ml, p = 0.02). Exercise pulmonary artery systolic pressures were 38 +/- 13 mm Hg before IAD, increased significantly to 46 +/- 11 mm Hg on day 1 (p = 0.03), and decreased below baseline values at 1 month to 31 +/- 12 mm Hg (p = 0.07). Peak A-wave velocities increased from 0.51 +/- 0.1 m/s after 1 day to 0.67 +/- 0.2 m/s after 1 month (p = 0.03). Restoration of sinus rhythm in patients with AF resistant to external electrical and/or pharmacologic cardioversion improves hemodynamic and cardiorespiratory function at daily activity exercise levels.

Right atrial appendage thrombosis in atrial fibrillation: its frequency and its clinical predictors.

This study assesses the incidence of right atrial (RA) chamber and appendage thrombosis in patients with atrial fibrillation (AF) in relation to RA appendage morphology and function. Transthoracic and multiplane transesophageal echocardiography were performed in 102 patients with AF to assess the incidence of RA and left atrial (LA) thrombi and spontaneous echo contrast. Both right and left ventricular sizes, atrial chamber and appendage sizes and function were measured. Twenty-two patients in sinus rhythm served as the control group (SR). Complete visualization of the RA appendage was feasible in 90 patients with AF. Patients with AF had lower tricuspid annular excursion (p = 0.008) and larger RA chamber area (p = 0.0001) than patients in SR. In addition, RA appendage areas were larger (p <0.05) and RA ejection fraction and peak emptying velocities (both p <0.0001) were lower in patients with AF patients than in those in SR. Equivalent differences were found for the LA appendage. Six thrombi were found in the RA appendage and 11 thrombi in the LA appendage in AF patients. Spontaneous echo contrast was found in 57% and 66% in the right atrium and in the left atrium, respectively. AF patients with RA appendage thrombi had a larger RA area (p = 0.0001), and lower RA appendage ejection fraction and emptying velocities (both p = 0.0001) than patients without thrombi. Spontaneous echo contrast was detected in all patients with thrombi. Spontaneous echo contrast was the only independent predictor of RA (p = 0.03) and LA appendage thrombosis (p = 0.036). In conclusion, multiplane transesophageal echocardiography allows the assessment of RA appendage morphology and function. RA spontaneous echo contrast is the only independent predictor of RA appendage thrombosis.

Temporal factors in the reduction of myocardial infarct volume by methylprednisolone.

With a canine model of myocardial infarction [ligation of the left anterior descending (LAD) coronary artery] and an intracellular stain for lactic dehydrogenase (LDH) to directly measure size of infarction, the influence of 30 mg. per kilogram of methylprednisolone sodium succinate was evaluted. The intravenous administration of a pharmacologic dose of methylprednisolone one, 2, or 3 hours after the onset of myocardial infarction significantly reduced the ultimate extent of myocardial necrosis, with the greatest reduction seen following the injection of the drug one hour after ligation. The left atrial pressure was significantly decreased by corticosteroid administration, whereas the cardiac index and peripheral vascular tone were improved insignificantly. Inconsistent and/or insignificant effects were observed in the systemic and coronary sinus blood gases and in those indices of myocardial metabolism which were determined. The potential impact of these findings on the clinical applicability of methylprednisolone sodium succinate in acute myocardial ischemia is discussed.

Oxygen uptake kinetics during low intensity exercise: relevance for rate adaptive pacemaker programming.

OBJECTIVE: To establish a normal database for oxygen uptake (VO2) kinetics during low intensity treadmill exercise (LITE) testing, to be used as a guideline for programming rate adaptive pacemakers, and to determine its relation to VO2 at anaerobic threshold and peak exercise. DESIGN: VO2 kinetics during LITE were compared with VO2 at anaerobic threshold and at peak exercise. SETTING: LITE testing is applicable during ambulatory or hospital care and can even be performed by patients with reduced cardiac capacity. PATIENTS: 60 healthy subjects (23 women, 51.6 (SD 20.4) years; 37 men, 42.2 (16.2) years). INTERVENTIONS: Treadmill exercise testing with "breath by breath" gas exchange monitoring using the LITE protocol for steady state, submaximal exercise, and the ramping incremental treadmill exercise (RITE) protocol for peak exercise. MAIN OUTCOME MEASURES: Mean response time of VO2, mean oxygen deficit, and VO2 at anaerobic threshold (VO2-AT) and at peak exercise (VO2-peak) were determined. RESULTS: (1) LITE protocol: mean response time of VO2 = 35.1 (9.9) s; oxygen deficit = 418.3 (47.9) ml; oxygen deficit/VO2 time index = 54.7 (7.4). (2) RITE protocol: VO2-AT = 22.1 (5.7) ml/kg/min; heart rate at anaerobic threshold = 120.1 (3.6) beats/min; VO2-peak = 37.6 (10.7) ml/kg/min; peak heart rate = 167.8 (19.3) beats/min. The mean response time and oxygen deficit/VO2 time index were significantly correlated to VO2-peak and VO2-AT (P < 0.01). CONCLUSIONS: VO2 kinetics calculated in healthy controls may serve as a control database for assessing the rate response programming of pacemakers and its influence on VO2 during LITE. Because aerobic capacity below the anaerobic threshold is more likely to represent activity in daily life and the kinetics of VO2 are significantly related to VO2 at anaerobic threshold and peak exercise, LITE may provide a clinically useful correlate to peak exercise testing.

Left atrial appendage function in patients with atrial flutter.

OBJECTIVE: To determine whether echocardiographic markers thromboembolic risk differ between patients with pure atrial flutter and patients with atrial flutter and intermittent atrial fibrillation. DESIGN: Patients with atrial flutter were followed up prospectively for 12 months to identify intermittent atrial fibrillation. After the follow up period, transthoracic and multiplane transoesophageal echocardiography were performed to assess left atrial chamber and appendage size, peak emptying velocities, and emptying fraction of the left atrial appendage. The presence of spontaneous echo contrast was also determined. SETTING: Tertiary cardiac care centre. PATIENTS: 20 consecutive patients with atrial flutter; 11 healthy subjects in sinus rhythm served as controls. RESULTS: Intermittent atrial fibrillation was documented in 11 patients by Holter monitoring or surface ECG; atrial fibrillation was not found in the other nine patients. Compared with the patients with pure atrial flutter, patients with atrial flutter and intermittent atrial fibrillation had larger left atrial chamber (mean (SD) 4.5 (0.6) v 3.8 (0.5) cm; 95% confidence interval 0.2 to 1.2; P = 0.01) and appendage areas (6.7 (2.2) v 4.8 (4.9) cm; 95% CI 0.4 to 3.5; P = 0.02), lower left atrial appendage emptying fractions (33 (11)% v 52 (11)%; 95% CI 8 to 29; P = 0.008), and also lower left atrial appendage emptying velocities (0.44 (0.21) v 0.79 (0.27) m/s; 95% CI 0.13 to 0.56; P = 0.005). In addition, a higher incidence of spontaneous echo contrast (11% v 36%) was observed in patients with atrial flutter and intermittent atrial fibrillation. CONCLUSIONS: Left atrial appendage function is depressed and spontaneous echo contrast more frequent in patients with atrial flutter and intermittent atrial fibrillation, as opposed to patients with pure atrial flutter. These data support the concept that patients with atrial flutter and intermittent atrial fibrillation have an increased risk of thromboembolic events and should therefore receive adequate anticoagulant treatment.

Connective tissue activation. XXIII. Increased plasma levels of a platelet growth factor (CTAP-III) in patients with rheumatic diseases.

Plasma levels of the CTAP-III antigen were measured by radioimmunoassay in 80 patients with rheumatic diseases. Patients with clear evidence of vasculitis usually exhibited increased plasma CTAP-III antigen. In both systemic lupus erythematosus and rheumatoid arthritis, there appeared to be a correlation between pCTAP-III values and other laboratory and clinical parameters of disease activity.

Histologic evidence of angiographic catheter-induced vascular trauma: a comparison of conventional and deformable soft-tip catheters.

Catheter-related complications associated with coronary arteriography remain an iatrogenic hazard with life-threatening consequences. Because such complications may be related to catheter-tip-induced vascular trauma during coronary angiography or percutaneous transluminal coronary angioplasty (PTCA), several types of deformable, soft-tip angiographic catheters have been developed. The following study was undertaken to evaluate the effects of one of these catheters, as well as of conventional catheters, in canine arteries. Ten dogs were catheterized, five with a conventional angiographic catheter and five with a deformable soft-tip catheter (Angiomedics SOFTIP model), all in the Judkins left 3.5 configuration. The left coronary artery (LCA) was subjected to repeated catheterization; the instruments were also advanced and withdrawn through various segments of the thoracic and abdominal aorta and the right iliac artery. Forty-five arterial tissue sections were collected; these were subjected to histologic analysis 2 weeks after catheterization. When catheterized with the soft-tip instrument, muscular arteries such as the LCA and the right iliac artery had an 86% reduction in subintimal lesions with a disrupted or split internal elastic membrane, compared to muscular arteries catheterized with a conventional instrument (p <.017). Moreover, two medial tears were produced by the conventional catheters. On a scale of 1 to 3 (3 being the most severe), the average severity of muscular arterial lesions observed after use of the soft-tip catheter was 1.0, whereas the average severity associated with conventional catheters was 2.0 (p <.02). No significant differences were observed in elastic (aortic) segments. Therefore, this study showed that subacute, subintimal vascular lesions induced by conventional angiographic catheters are more frequent, more serious, and more likely to penetrate the internal elastic membrane than are lesions produced by soft-tip catheters. Obviously, then, soft-tip catheters offer a safer, less traumatic approach to diagnostic and interventional cardiology.

Localized nodular synovitis of the knee: a case report.

A 25-year-old man with chronic swelling of the right knee had a mass that was eventually palpated in the suprapatellar pouch. Arthrotomy and biopsy revealed localized nodular synovitis. Since surgical excision of the mass the patient has been asymptomatic. While localized nodular synovitis generally appears as an internal derangement of the joint, this patient had signs and symptoms of chronic monoarthritis.

First clinical results with a new temperature-controlled rate-responsive pacemaker. Comparison of Activitrax and Nova MR pacemakers with VVI/AAI pacing.

We examined the cardiopulmonary effects of maximum bicycle ergometer exercise in seven patients with implanted Intermedics Nova MR pacemakers for three types of pacing in a randomized sequence: VVI or AAI at 70 beats/min (SSI 70), rate-adaptive temperature-controlled pacing with the implanted Nova MR, and rate-adaptive activity-controlled pacing with a Medtronic Activitrax pacemaker taped to the chest wall, which triggered the implanted Nova MR in the VVT or AAT mode by skin electrodes. The maximum exercise tolerance was 67 W with SSI 70, 71 W with Activitrax pacing, and 91 W with Nova MR pacing; the maximum oxygen uptake as 17.6, 19.5, and 21.5 ml/min/kg, respectively. The highest heart rate achieved was 81 beats/min with SSI 70, 98 beats/min with the Activitrax, and 118 beats/min with the Nova MR on average; the mean rate increase from rest to maximum exercise was 11, 29, and 47 beats/min, respectively. With both rate-adaptive types of pacing (Nova MR and Activitrax), an increase in exercise tolerance and maximum heart rate could be achieved, but this increase was significantly more obvious with the temperature-controlled Nova MR than with the activity-controlled Activitrax. However, with a different form of exercise, for example, treadmill ergometry, the rate response of the Activitrax would presumably have been somewhat clearer.

[Cardiopulmonary stress test in variable frequency stimulation: a comparison of Activitrax and Nova-MR pacemakers in VVI/AAI stimulation]. / Kardiopulmonale Belastungstests unter frequenzvariabler Stimulation: Ein Vergleich von Activitrax- und Nova-MR-Schrittmachern zu VVI-/AAI-Stimulation.

In seven patients with implanted intermedics NOVA MR pacemakers, we examined the cardiopulmonary effects of maximum bicycle ergometer exercise for three types of pacing in a randomized sequence: VVI or AAI at 70/min (SSI 70), rate adaptive temperature controlled with the implanted NOVA MR, and rate adaptive activity controlled by means of a Medtronic Activitrax pacemaker taped to the chest wall, which triggered the implanted Nova MR in the VVT or AAT mode via skin electrodes. The maximum exercise tolerance was 67 W with SSI 70, 71 W with Activitrax and 91 W with Nova MR. The maximum oxygen uptake was accordingly 17.6 ml/min/kg with SSI 70, 19.5 ml/min/kg with Activitrax, and 21.5 ml/min/kg with Nova MR. The highest heart rate reached was 81 beats/min with SSI 70,98 beats/min with Activitrax and 118 beats/min with Nova MR. The rate increase from rest to maximum exercise was 11 beats/min with SSI 70,29 beats/min with Activitrax and 47 beats/min with Nova MR. An increase in exercise tolerance and maximum heart rate could be achieved with both rate adaptive types of pacing, but significantly more clearly with the temperature controlled Nova MR than with the activity controlled Activitrax. However, using a different form of exercise, e.g. treadmill ergometry, the rate response of the Activitrax would presumably have been somewhat clearer.

Relationship between nailfold capillary abnormalities and organ involvement in systemic sclerosis.

Nailfold capillary abnormalities in 42 consecutive patients with systemic sclerosis were studied by wide field capillary microscopy, and capillary abnormalities were correlated with organ involvement. Twenty-eight patients hd diffuse skin disease, and 14 had the CREST variant of systemic sclerosis (calcinosis, Raynaud's phenomenon, esophageal dysmotility, sclerodactyly, telangiectasis) with anticentromere antibodies. Nailfold capillary enlargement and loss were graded from photographs. There was no correlation between the severity of either nailfold capillary loss or enlargement and duration of disease, number of organ systems involved, or acroosteolysis. The presence of telangiectasis correlated with extreme capillary enlargement (P less than 0.025). Based on these findings it can be concluded that nailfold capillary changes in individual patients with systemic sclerosis are not useful in predicting organ involvement.

Hemodynamic effects of slow and rapid defibrination with defibrizyme, the thrombin-like enzyme from venom of the timber rattlesnake.

The hemodynamic response to slow and rapid defibrination was sutdied in anesthetized beagle dogs, with the following results: 1. Slow defibrination was a benign procedure that had little or no effect on the hemodynamic variables studied. 2. Rapid defibrination induced statistically significant decreases in cardiac output, stroke volume, and mean aortic arterial pressure. 3. Bradycardia, a drop in mean left v"ntricular pressure, cardiac and minute work indices, an increase in pulmonary artery pressure, and a drastic rise in pulmonary and systemic vascular resistances were also observed. Although physiologically apparent, these changes were not statistically significantly different from control levels. 4. Pulmonary capillary wedge pressure, left ventricular end-disatolic pressure, arterial pH, and blood gases were not altered by rapid defibrination. 5. In view of the similarities between the hemodynamic changes observed after rapid defibrination and acute myocardial ischemia, the role of decreasing fibrinogen concentrations and blood viscosity in aucte myocardial infarction and the sudden death syndrome is questioned.

Physiologic benefits of rate responsiveness.

Increases in metabolic demand in response to routine activities and exercise are met through greater cardiac output and oxygen delivery. Patients with fixed-rate pacemakers cannot increase heart rate and must rely solely on increases in stroke volume to provide the necessary adjustments in cardiac output. These compensatory stroke volume increases limit the fixed-rate pacemaker patient's ability to meet the demand of their daily routine. A physiological, rate responsive pacemaker was studied and it was found to increase maximum exercise tolerance from 4.4 +/- .62 METS paced VVI at 65 ppm to 8.1 +/- .71 METS when the same patients were paced rate responsively at an average rate of 91 +/- 3.8 ppm. Animal studies were used to quantify the limitation in stroke volume reserve. Maximum increases of 55.8 +/- 3.7% over resting values were seen in animals in complete heart block at pacing rates of 100 ppm during strenuous exercise. Higher pacing rates increased cardiac output at the same exercise intensity, from 4.94 +/- .72 lpm at 100 ppm to 7.66 +/- 1.02 lpm at 250 ppm. A pacemaker that increases pacing rate in response to greater metabolic demand will maintain stroke volume and end-diastolic volume at near normal values while providing significant improvement in cardiac output and work capacity.