J B Lakier

Inadvertent Malposition of a Transvenous-lnserted Pacing Lead in the Left Ventricular Chamber

In conclusion, we propose the following approach to prevent and manage lead malposition in the left ventricle: A 12-lead electrocardiogram in the paced mode and an anterior and lateral chest view should be thoroughly inspected shortly after pacemaker implantation. A definitive diagnosis of malposition can be established with these tests. Development of any neurologic symptoms should be attributed to the malpositioned lead until proved otherwise. In such patients, serious consideration should be given to transcatheter or surgical lead extraction after a period of anticoagulation. If this is not possible, chronic anticoagulation with warfarin must be initiated, achieving an international normalized ratio of > or = 2.5. Antiplatelet therapy alone may not confer adequate protection against future cerebral events. Furthermore, most patients with neurologic manifestations do not have echocardiographic evidence of thrombus on the lead. Conversely, presence of thrombus is highly associated with neurologic symptoms. Any intraarterial lead must be removed due to inevitable complications. Patients who have remained completely asymptomatic for > or = 3 years may be followed carefully with no therapy. For asymptomatic patients diagnosed before this time period, we recommend empiric therapy with antiplatelet agents or low-dose warfarin (international normalized ratio 1.5-2) with careful observation for symptoms.

Frequency spectrum of the aortic component of the second heart sound in patients with normal valves, aortic stenosis and aortic porcine xenografts: Potential for detection of porcine xenograft degeneration☆

The frequency spectrum of the aortic component of the second sound (A2) was measured noninvasively in 77 patients. Fourteen had a normal aortic valve, 14 had calcific aortic stenosis and 49 had an aortic porcine xenograft. Phonocardiograms were recorded on magnetic tape on line with a Spectral Dynamics signal processor with which the frequency spectrum and dominant frequency of A2 were determined. In 14 patients with a normal aortic valve, the dominant frequency of A2 was 53 ± 3 hertz (mean ± standard error of the mean); in 14 patients with aortic stenosis A2 frequency was higher, 87 ± 5 hertz (p < 0.001). In 15 patients with a porcine aortic valve heterograft implanted for 18 months or less, A2 frequency was 48 ± 5 hertz, which did not differ significantly from that of patients with a normal natural aortic valve. However, in 19 patients with an aortic porcine heterograft that was in place 5 to 7.5 years, the dominant frequency of A2 was higher, 81 ± 4 hertz (p < 0.001), and within the range of that observed in patients with aortic stenosis. Among these 19 patients, 2 required replacement of the prosthetic aortic valve because of valve degeneration. The association of a higher than normal frequency of A2 with a stiffened valve, such as occurs in aortic stenosis, is predictable on the basis of factors that affect the frequency of valve vibration and pressure fluctuations productive of sound. The data suggest that the frequency of A2 may be of value in detecting degenerative changes of porcine aortic xenografts.

Non-ejection systolic clicks and mitral systolic murmurs in black schoolchildren of Soweto, Johannesburg.

A survey was conducted on 12 050 Black schoolchildren, aged 2 to 18 years, in the South Western Townships of Johannesburg (Soweto), and the prevalence of non-ejection systolic clicks and late systolic murmurs was determined. One or both of these auscultatory findings were detected in 168 children, yielding a prevalence rate of 13-99 per 1000 in the school population. A female preponderance of 1-9:1 was present and there was a strong linear increase in prevalence with age, with a peak rate of 29-41 per 1000 in 17-year-old children. A non-ejection click was the only abnormal auscultatory finding in 123 children (73%) and a mitral systolic murmur in 8 (5%), whereas in 37 (22%) both these findings were present. Of the latter 37 children, the murmur was late systolic in 32; in 5 it was early systolic. Auscultation in different postures was important in the detection of both non-ejection clicks and mitral systolic murmurs. Experience in the detection of these auscultatory findings influenced the frequency with which they were heard. Electrocardiographic abnormalities compatible with those previously described in the billowing mitral leaflet syndrome were present in 11 of 158 children. The aetiology of these auscultatory findings in this community remains unknown. In the same survey, a high prevalence rate of rheumatic heart disease was recorded and the epidemiology of the non-ejection clicks and these mitral systolic murmurs showed similarties to that of rheumatic heart disease. Though the specific billowing mitral leaflet syndrome almost certainly accounts for some of these auscultatory findings, a significant proportion may have early rheumatic heart disease. Further elucidation of this problem is necessary.

Cardiac troponin I and cardiac enzymes after electrophysiologic studies, ablations, and defibrillator implantations

Diagnostic electrophysiologic studies and defibrillator implantations with subsequent test discharges from the defibrillator do not cause an elevation in cardiac troponin I levels. All patients with an ablation had an elevation in the cardiac troponin I levels.

First pass Tc-99m MIBI ventriculography in the assessment of left ventricular diastolic function. A comparison with Doppler echocardiography.

Tc-99m MIBI is used for myocardial imaging and first-pass studies. However, little is known about its utility in the assessment of left ventricular diastolic function. The authors retrospectively compared first pass studies of Tc-99m MIBI at rest with Doppler flow velocity measurements to assess left ventricular diastolic performance. Thirty-nine patients who had both studies performed within 48 hours of each other were evaluated. Three indices of diastolic function were measured by first pass Tc-99m MIBI ventriculography and Doppler echocardiography: 1) Time to peak early diastolic velocity; 2) normalized peak filling rate; and 3) half filling fraction. The results demonstrated a correlation of 0.82 (P < 0.001), 0.82 (P < 0.001), and 0.53 (P = 0.001) for the above indices, respectively. This study indicates that the indices of left ventricular diastolic function by first pass Tc-99m MIBI compare favorably with those derived from Doppler flow velocity measurements in which the diagnostic value has been previously established. Both methods accurately reflect diastolic flow and may facilitate clinical evaluation of diastolic function.

Tricuspid component of first heart sound.

Right and left atrial pressures with a simultaneous external phonocardiogram and standard lead II electrocardiogram were recorded during routine cardiac catheterization in i5 patients. With one exception, the onset of the second (T1) major component of the first sound coincided with the peak of the right atrial c wavejust as the major left-sided component (M1), previously studied in this laboratory, coincides with the peak of the left atrial c wave. Right and left atrial c waves were synchronous in the exception and in that instance separate major components were not identified. These observations provide further evidence that T1 arises at the tricuspid valve. Analogous to the mode ofproduction ofM1, it is believed that after tricuspid valve closure the apposed leaflets are billowed into the right atrial cavity resulting in right atrial c waves, at the peak of which tension on the chordae tendineae and leaflets themselves produces T1. Some factors affecting the timing and intensity ofM1 and T1 are mentioned.

Mitral valve aneurysm after infective endocarditis in the billowing mitral leaflet syndrome

Mitral valve aneurysm is an uncommon complication of infective endocarditis. This report describes a patient with severe regurgitation due to perforations in a mitral aneurysm who required mitral valve replacement 9 years after a staphylococcal infection was superimposed on a billowing mitral leaflet. The unusual auscultatory signs and angiographic appearance could have led to diagnosis of the aneurysm.

Initial Results, Predictors of Success, and Long-Term Outcome of Primary Coronary Angioplasty for Acute Myocardial Infarction in a Community Hospital

W favorable results with primary coronary angioplasty (PCA) in patients with acute myocardial infarction (AMI) can be achieved in a community hospital has not been well established. In our community hospital, we have been using PCA as the exclusive reperfusion modality for AMI since 1994. This retrospective study was conducted to analyze our results, including the factors predictive of success and the impact of a successful PCA on hospital stay and on long-term outcome. • • • We retrospectively analyzed 153 consecutive patients who underwent PCA for AMI at our hospital from April 1, 1997 to June 30, 1998. All patients presented to our emergency department within 12 hours of symptom onset with

Role of Duplex Imaging in Intermnediate Category Ventilation Peffusion Scans: Experience of a Conmmnunity Hospital

1 mm of ST-segment elevation in

Four year follow-up of Black schoolchildren with non-ejection systolic clicks and mitral systolic murmurs

2 contiguous leads on the initial electrocardiogram. Patients received a chewable adult aspirin (325 mg), weight-adjusted heparin bolus, and b blockers and/or nitrates as determined by their physicians. All patients with persistent angina or elevated ST segments despite initial medical treatment were taken directly to the cardiac catheterization laboratory and constitute the study population. PCA was performed via the percutaneous femoral approach using the standard technique. One of 10 cardiologists with credentials in acute PCA performed the procedure. Glycoprotein IIb/IIIa inhibitors were used at the discretion of the physician, primarily when intracoronary thrombus was identified by angiography. Stents were used at the discretion of the operator. Additional lesions were not treated during the initial procedure. Activated clotting time was maintained at