David T. Kawanishi

Recommendations for Extraction of Chronically Implanted Transvenous Pacing and Defibrillator Leads: Indications, Facilities, Training

The procedure of lead removal has recently matured into a definable, teachable art with its own specific tools and techniques. It is now time to recognize and formalize the practice of lead removal according to the current methods of medicine and the health care industry. In addition, since at this time the only prospective scientific study of lead extraction is the PLEXES trial, we suggest that studies relating to the techniques of and indications for lead extraction be designed. Recommendations for a common set of definitions, for a framework of training and reviewing physicians in the art, for general methods of reimbursement, and for consistency among clinical trials have been made. Implementation of these recommendations will require additional effort and cooperation from practicing physicians, medical societies, hospital administrations, and industry.

Mechanisms of increase in mitral valve area and influence of anatomic features in double-balloon, catheter balloon valvuloplasty in adults with rheumatic mitral stenosis: a Doppler and two-dimensional echocardiographic study.

To study the mechanism of increase in the mitral valve area (MVA) and the anatomic features of the mitral valve that may affect the results of catheter double-balloon valvuloplasty (CBV) in adult patients with mitral stenosis, Doppler and two-dimensional echocardiography was performed in 12 patients before and immediately after CBV. Immediately after CBV, there was an increase in the transverse diameter of the mitral valve orifice from 18 +/- 1.6 to 25 +/- 2.8 mm (mean +/- SD, p less than .001). The anterior angles at the commissure increased from 33 +/- 6 to 57 +/- 20 degrees (p less than .05) and the posterior angles from 36 +/- 9 to 54 +/- 14 degrees (p less than .05). The MVA was greater after CBV in patients with pliable mitral valves (2.6 +/- 0.7 cm2) compared with those with rigid mitral valves (1.9 +/- 0.8 cm2; p = .08). After CBV, MVA was smaller in patients with calcification (2.1 +/- 0.2 cm2) compared with those without (2.7 +/- 0.5 cm2; p = .10) and in those with subvalvular disease (2.0 +/- 0.6 cm2) compared with those without (2.9 +/- 0.9 cm2;p = .03). The MVA by Doppler ultrasound before CBV (1.0 +/- 0.2 cm2) correlated well with MVA by cardiac catheterization (1.0 +/- 0.3 cm2; r = .8, SEE = 0.2 cm2). After CBV, the correlation of MVA by Doppler ultrasound (2.0 +/- 0.5 cm2) with MVA by cardiac catheterization (2.4 +/- 0.8 cm2) was poor (r = .3, SEE = 0.44 cm2).(ABSTRACT TRUNCATED AT 250 WORDS)

Risks of spontaneous injury and extraction of an active fixation pacemaker lead: Report of the Accufix Multicenter Clinical Study and Worldwide Registry

BACKGROUND The Telectronics Accufix pacing leads were recalled in November 1994 after 2 deaths and 2 nonfatal injuries were reported. This multicenter clinical study (MCS) of patients with Accufix leads was designed to determine the rate of spontaneous injury related to the J retention wire and results of lead extraction. METHODS AND RESULTS The MCS included 2589 patients with Accufix atrial pacing leads that were implanted at or who were followed up at 12 medical centers. Patients underwent cinefluoroscopic imaging of their lead every 6 months. The risk of J retention wire fracture was approximately 5.6%/y at 5 years and 4.7%/y at 10 years after implantation. The annual risk of protrusion was 1.5%. A total of 40 spontaneous injuries were reported to a worldwide registry (WWR) that included data from 34 672 patients (34 892 Accufix leads), including pericardial tamponade (n=19), pericardial effusion (n=5), atrial perforation (n=3), J retention wire embolization (n=4), and death (n=6). The risk of injury was 0.02%/y (95% CI, 0.0025 to 0. 072) in the MCS and 0.048%/y (95% CI, 0.035 to 0.067) in the WWR. A total of 5299 leads (13%) have been extracted worldwide. After recall in the WWR, fatal extraction complications occurred in 0.4% of intravascular procedures (16 of 4023), with life-threatening complications in 0.5% (n=21). Extraction complications increased with implant duration, female sex, and J retention wire protrusion. CONCLUSIONS Accufix pacing leads pose a low, ongoing risk of injury. Extraction is associated with substantially higher risks, and a conservative management approach is indicated for most patients.

Changes in blood rheology in patients with stable angina pectoris as a result of coronary artery disease.

We investigated several rheologic variables in 17 patients (11 men, six women, mean age = 52.1 +/- 9.8 years) with chronic stable angina. None took any medication except for sublingual nitroglycerin for 2 weeks before the study, and all had angiographically proven coronary artery disease with no history of myocardial infarction. Rheologic measurements included hematocrit, whole blood and plasma viscosity (750 and 1500 sec-1), degree of red cell aggregation via the zeta sedimentation ratio, and the extent and rate of red cell aggregation after stasis (Myrenne aggregometer). Compared with normal control donors, salient observations in the patients as a group included: a small (6%) but significant increase in hematocrit, a significant elevation in plasma viscosity (9%), significant increases in whole blood viscosity at both shear rates (14% and 16%), significant increases in the degree (12%), the extent (41%), and the rate (28% faster time constant) of red cell aggregation, an elevated alpha 2 level (15% increase) and a significantly increased fibrinogen concentration (25% increase), both of which correlated with the enhanced red cell aggregation. Rheologic abnormalities were evident when patients with disease in either one vessel or two to three vessels were compared with controls, but differences between these subgroups of patients were not significant. We conclude that patients with angina have rheologic abnormalities that are compatible with disturbed blood flow and an enhanced tendency for coronary arterial thrombosis.

Influence of mitral valve morphology on double-balloon catheter balloon valvuloplasty in patients with mitral stenosis. Analysis of factors predicting immediate and 3-month results.

To determine if mitral valve morphology influences the results of double-balloon catheter balloon valvuloplasty (CBV) for mitral stenosis, two-dimensional echocardiography was performed in 33 patients before CBV. The two-dimensional echocardiographic features of leaflet motion, leaflet thickness, subvalvular disease, and commissural calcium and 14 pre-CBV clinical and hemodynamic variables were then correlated to the immediately post-CBV mitral valve area (MVA). At 3 months after CBV, the two-dimensional echocardiographic features of patients with a 25% or greater decrease in MVA were analyzed to determine whether mitral valve morphology had influenced early results. Leaflet motion had a significant relation with the immediately post-CBV MVA (r = 0.67, y = 4.5x + 0.29, and SEE = 0.45). Leaflet thickness had a weak and negative relation (r = -0.48, y = -0.17x + 2.6, and SEE = 0.53) with the immediately post-CBV MVA. Subvalvular disease and commissural calcium had no significant relation to the immediately post-CBV MVA. When leaflet motion and leaflet thickness were considered as grades of mild, moderate, and severe and assigned a score of 0-2, patients with more severe disease (total score, 3 or 4) had a significant lower MVA immediately after CBV (1.4 +/- 0.4 cm2) than patients with moderate disease (score, 1-2; MVA, 2.0 +/- 0.5 cm2; p less than 0.05) or mild disease (score, 0; MVA, 2.6 +/- 0.6 cm2; p less than 0.05). In 96% of patients with a total score of 0-2, the immediately post-CBV MVA was more than 1.4 cm2, whereas only 29% of patients with a total score of 3-4 had an immediately post-CBV MVA of more than 1.4 cm2. Analysis of all two-dimensional echocardiographic features showed that leaflet motion score had the strongest influence on the post-CBV MVA (p less than 0.001). When all two-dimensional echocardiographic, clinical, and hemodynamic variables were included, leaflet motion, effective balloon dilating area, and cardiac output were the strongest predictors of the immediate post-CB MVA.(ABSTRACT TRUNCATED AT 400 WORDS)

Mitral valve aneurysm: Clinical features, echocardiographic-pathologic correlations

Aneurysm of the mitral valve occurs most commonly in association with infective endocarditis of the aortic valve. The probable mechanism of its formation is destruction of the aortic valve which results in a regurgitant jet that strikes the anterior leaflet of the mitral valve, creating a secondary site of infection leading to the development of an aneurysm. Perforation of these aneurysms may occur, resulting in mitral regurgitation and pulmonary edema from a ventricle already volume overloaded from aortic regurgitation. This report describes the clinical and echocardiographic-pathologic findings in five patients with pathologically proven aneurysm of the mitral valve. There are no clinical features that appear specific for this abnormality. The two-dimensional echocardiographic feature that is helpful in the diagnosis is a bulge of the mitral valve leaflet toward the left atrium that persists throughout the cardiac cycle. Preoperative diagnosis is important because a mitral valve aneurysm may produce serious complications and is frequently overlooked during surgery. Repair of the aneurysm may be feasible; otherwise, valve replacement becomes necessary. Careful two-dimensional echocardiographic examination should be done in patients with left-sided infective endocarditis to detect an aneurysm of the mitral valve.

Response of angina and ischemia to long-term treatment in patients with chronic stable angina: A double-blind randomised individualized dosing trial of nifedipine, propranolol and their combination☆

Seventy-four patients with chronic stable mild angina, mild coronary artery disease (83% had one- or two-vessel disease) and normal left ventricular function were studied to measure the response of treadmill exercise performance and painful and silent ischemia in the ambulatory setting to randomly assigned treatment with nifedipine or propranolol and their combination; titration to maximal tolerated dosages was performed in double-blind manner. At 3 months both nifedipine and propranolol reduced the weekly angina rate (p less than 0.05); during treadmill exercise testing, increases (p less than 0.05) were noted in time to angina and total exercise time and decreases in maximal ST depression at the end of exercise. There were no differences between the responses to nifedipine and propranolol and no significant additional changes were seen after another 3 months of therapy. The combination of nifedipine and propranolol reduced the number of patients with angina on exercise treadmill testing from 64% to 38% (p less than 0.05). During ambulatory electrocardiographic monitoring before treatment, there were 1.4 +/- 2.4 (mean +/- SD) episodes/24 h of painful ischemia and a very low silent ischemia frequency: mean 1.1 +/- 2.7 episodes/24 h, mean duration 16 +/- 25 min/24 h. Treatment with propranolol and nifedipine resulted in reduction of episodes and duration of painful and painless ischemia; approximately 77% of patients were free of all ischemic episodes. It is concluded that patients with chronic stable mild angina have a low incidence of silent ischemia. Nifedipine or propranolol alone, titrated to individualized maximally tolerated dosages, are equally effective in long-term control of painful and painless ischemia, anginal episodes and exercise-induced ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of Doppler echocardiographic and hemodynamic indexes of left ventricular diastolic properties in coronary artery disease

Transmitral flow velocity was measured by Doppler echocardiography in 15 patients with coronary artery disease simultaneously with high-fidelity recording of left ventricular pressure. Doppler echocardiographic recordings were also performed in 14 age- and heart rate-matched normal subjects. Statistically significant differences (p less than 0.05) in acceleration half-time (55.3 +/- 8.2 vs 70.4 +/- 14.9 ms), deceleration half-time (83.1 +/- 17.9 vs 109.5 +/- 18.1 ms), deceleration rate (4.9 +/- 0.9 vs 3.1 +/- 0.9 m/s2), peak velocity of early diastolic left ventricular inflow (E wave) (0.78 +/- 0.13 vs 0.61 +/- 0.13 m/s) and A/E ratio (0.74 +/- 0.20 vs 0.98 +/- 0.31) between normal subjects and patients were noted. There was no significant difference in peak velocity of atrial systolic flow (A wave) between normal subjects and patients. Correlation between transmitral flow indexes and hemodynamic indexes of left ventricular diastolic properties were poor, with r values ranging from 0.02 to 0.65. Significant correlations between deceleration rate versus maximal isovolumic left ventricular pressure decrease (maximum -dP/dt) and A wave versus maximum -dP/dt (p less than 0.05) were found (0.53 and 0.65, respectively). Deceleration rate was the most sensitive index of isovolumic relaxation assessed by hemodynamic methods, whereas the A/E ratio was a poor indicator of hemodynamic measurements of isovolumic relaxation. An abnormal deceleration rate had 100% specificity for detecting abnormal maximum -dP/dt, while abnormal acceleration half-time, deceleration half-time and A/E ratio had 80% specificity for detecting abnormal time constant. The deceleration rate, acceleration half-time, deceleration half-time and A/E ratio had a predictive value of 60 to 100% for the detection of abnormal maximum -dP/dt and time constant.

Identification of the increased frequency of cardiovascular abnormalities associated with mitral valve prolapse by two-dimensional echocardiography.

Two-dimensional echocardiography (2-D echo) was performed in 86 consecutive patients with mitral valve prolapse (MVP) and in 25 normal subjects. In normal subjects, mitral leaflet thickness was 3.5 +/- 0.8 mm (mean +/- standard deviation) and the mitral leaflet thickness to aortic wall thickness ratio was 1.0 +/- 0.2. Patients with MVP were separated into 2 groups: those with normal mitral thickness (less than or equal to mean + 2 SD observed in normal subjects, i.e., less than or equal to 5.1 mm) and normal mitral thickness to aortic wall thickness ratio (less than or equal to mean + 2 SD observed in normal subjects, i.e., less than or equal to 1.4) (group I) and others in whom these values were increased (group II). In group I, mitral thickness was 3.6 +/- 0.6 mm and mitral thickness to aortic wall thickness ratio was 1.1 +/- 0.1, and in group II, mitral thickness was 8.8 +/- 1.2 mm and mitral thickness to aortic wall thickness ratio was 2.2 +/- 0.5. The only significant cardiovascular abnormalities in group I were mitral regurgitation in 2 patients and tricuspid valve prolapse in 1 patient. In group II, 7 patients had clinically significant mitral regurgitation, 8 had aortic root abnormalities, 4 had tricuspid valve prolapse and 6 had Marfans syndrome. Cardiovascular abnormalities were present in 60% (18 of 30) of patients in group II and in 6% (3 of 56) of patients in group I (p less than 0.001). Two-dimensional echo enabled the identification of a subset of patients with MVP who had thickened mitral leaflets. These patients had an increased incidence of cardiovascular abnormalities.

Accuracy of evaluation of the presence and severity of aortic and mitral regurgitation by contrast 2-dimensional echocardiography

Abstract Contrast 2-dimensional (2-D) echocardiography was performed during cardiac catheterization to compare the technique with cineangiography in evaluating the presence and severity of aortic (AR) and mitral regurgitation (MR). A physiologic solution was injected through the intracardiac catheter while echocardiograms were recorded in multiple views. AR was evaluated in 35 patients; an adequate 2-D echocardiogram was obtained in every patient. Cineangiography was adequate for diagnosis in every patient, but in 3 patients AR could not be graded because of technical problems. Twenty-six patients had AR by 2-D echocardiography and cineangiography and 9 did not have AR by either 2-D echocardiography or cineangiography. Thus, the specificity, sensitivity and predictive accuracy was 100% for detection of AR by 2-D echocardiography. Severity of AR was graded (0 to 4+) by visual inspection in both methods, and severity by both methods correlated with r = 0.998. MR was evaluated in 59 patients. Because of technical problems, MR could not be evaluated by cineangiography in 15, by 2-D echocardiography in 5, or by either method in 2. In 2 patients, although it could be detected, the severity of MR could not be graded by cineangiography. Of 37 patients with satisfactory studies, MR was detected by 2-D echocardiography and by cineangiography in 16; MR was detected only by 2-D echocardiography in 2, only by cineangiography in 3 and by neither method in 16. The sensitivity of 2-D echocardiography for detection of MR was 84%, specificity 89%, positive predictive accuracy 89%, and negative predictive accuracy 84% compared with cineangiography. The severity of MR by both methods correlated with r = 0.998. Contrast 2-D echocardiography for the evaluation of the presence and severity of AR and MR is both sensitive and specific, particularly for AR. In the cardiac catheterization laboratory, this method should be of greatest value when use of cineangiography is limited by the dose of contrast medium, radiation or by technical problems, particularly those encountered with left ventricular angiography.