Peripartum cardiomyopathy treated with a left ventricular assist device as a bridge to cardiac transplantation.

Peripartum cardiomyopathy is a congestive cardiomyopathy that occurs within the last month of pregnancy or first six months after delivery. Early diagnosis and prompt treatment are of paramount importance. Our patient did not respond to conventional therapy and needed a left ventricular assist device and subsequent orthotopic cardiac transplantation to survive.

Friedreich's ataxia associated with hypertrophic cardiomyopathy and coronary vasospasm.

A rare patient with Friedreich's ataxia and hypertrophic obstructive cardiomyopathy who showed evidence of coronary artery vasospasm on ambulatory electrocardiographic monitoring is presented.

Analysis of PR subintervals in normal subjects and early studies in patients with abnormalities of the conduction system using surface His bundle recordings.

Utilizing several different approaches to noise reduction, satisfactory beat by beat His bundle activity was recorded from the chest surface in 41 (80%) of 52 normal subjects. Surface atrial to His intervals (PAH) and His to ventricular intervals (HV) were measured in this group and compared with subintervals of the PR segment recorded endocardially from 47 persons with normal electrophysiologic findings. A recent modification in the selection algorithm allows on-line identification of the four of five possible recording sites for utilization in a spatial summation. The ability to record in less favorable circumstances has been improved to the extent that records of suitable clarity for measurement were also obtained in 17 (77%) of 22 individuals with conduction system abnormalities. Comparison of the surface and endocardially acquired data in the normal group reveals no statistically significant difference in the surface acquired PAH and endocardially acquired high right atrial to His (HRAH) intervals, nor in the HV intervals. In a small subset of patients data were acquired by both techniques and no significant differences were found. Thus, when programmed stimulation or endocardial mapping is not required to answer specific clinical questions, in the majority of persons it is possible to record meaningful subintervals from the body surface from each cardiac cycle. Additionally, in instances in which surface P wave activity is obscure in the routine electrocardiogram, this technique enhances atrial electrical activity.

Comparison of total body surface map depolarization patterns of left bundle branch block and normal axis with left bundle branch block and left-axis deviation.

Total body surface maps from 15 subjects with left bundle branch block and normal axis (LBBB-NA) and 10 subjects with left bundle branch block and left axis (LBBB-LA) were analyzed and compared with maps from normal subjects. In 19 of the 25 subjects with LBBB, the timing of early upper sternal positivity was similar to that of normal subjects, indicative of timely but oppositely directed septal activation. The right ventricular breakthrough was normally located in all, but was earlier after the onset of QRS than expected in some. The initial portion of the positivity produced by left ventricular activation was located in the upper anterior chest in both LBBB-NA and LBBB-LA, but its onset was generally delayed compared with that in normal subjects, presumably because of the time taken by the right-to-left septal activation. Also, the total duration of this positivity was longer than in normal subjects and extended considerably beyond 90 msec, indicating prolonged activation of the anterior free wall of the left ventricle. In LBBB-NA, this upper anterior positivity remained anterior throughout depolarization, but in LBBB-LA it moved toward the left shoulder and the left upper back, presumably due to the posterior orientation of the terminal portion of depolarization. This terminal orientation in patients with LBBB-LA was thought to be due to the additional delay in the activation of the anterobasal portion of the left ventricle caused by selective involvement of the left anterior fascicle.

The pathologic correlates of the electrocardiogram: complete left bundle branch block.

To assess whether gross pathologic differences exist between hearts with left bundle branch block (LBBB) and left-axis deviation (LAXD) and those with LBBB and a normal frontal plane axis, we examined 70 hearts with LBBB in a series of 1410 sequential dissections (5%). Thirty-two hearts had LAXD and 34 had normal axes on the correlative ECG. Left ventricular enlargement occurred frequently (93%). No significant differences were found in age distribution, left ventricular weight, coronary anatomy or infarct location. Quantitative analysis revealed larger inferoposterolateral and apical infarcts in hearts with LBBB and LAXD (p less than 0.01). The accuracy of various electrocardiographic signs of left ventricular enlargement and myocardial infarction in the presence of LBBB was assessed. Voltage criteria and QRS duration poorly define anatomic chamber enlargement. Anterior infarction is suggested by a q or pathological Q wave in lead I, a q wave in leads I, V5 and V6, or notched S waves in V3 or V4. Pathologic q waves or ST shifts in the inferior leads have high diagnostic specificity but low sensitivity for inferior infarction.

A dynamic electrical record of the pathway of human His bundle activation from surface mapping.

Body surface potential maps of human His bundle activity have been difficult to product for two reasons: (1) The peak surface potentials are often less than 5 muv, and (2) the simultaneous atrial repolarization potentials frequently exceed 100 muv. We have therefore amplified surface signals 25 times the standard gain of 1000, and then removed by cross-correlation the static pattern of atrial repolarization for serial 1-msec maps of the P-R segment in five normal men. A consistent finding emerged: a positive anterior chest peak appeared 40 msec before QRS onset, and then-within 10 msec-spread out into a long, low transverse mound before disappearing in 5 more msec. The map data were analytically converted to serial electrical sources: the center of electrical activity moved first slightly down, then directly forward, before retracing its path and disappearing. The retrace and accompanying surface spread-out strongly suggests diverging dipolar sources. Thus the data fit a simple heart source which moves anteriorly and then breaks into two (right and left)-as expected from activation of the bundle of His and its bifurcation into left and right bundle branches.

The determination of the human ventricular gradient from body surface potential map data.

We have analyzed the Wilson ventricular gradient in terms of body surface potential maps and of the reduction of such surface patterns to equivalent dipoles or vectors. While the ventricular gradient traditionally was treated as first a scalar, then a vector concept, we found that the three entities (QRS area, T area, QRST area) did not reduce to vectors with a common location. However, conventional vector addition (QRST area = QRS area + T area) did precisely apply. Further we found considerable more-than-vector or extra-dipolar information remaining for all three entities after removal of the dipole effect. This suggests that maps of these entities should be considered the boundaries of complex electrical fields rather than simple surface effects of vectors.

Surface recording of His-Purkinje activity on an every-beat basis without digital averaging.

Efforts to record evidence of electrical activity from the body surface originating in the His bundle or bundle branches have been reported since 1973. Almost exclusively, these techniques have required digital averaging of 50-100 sequential cardiac cycles. For immediate diagnostic, therapeutic and prognostic application, recording on an every-beat basis is highly desirable. This is especially important in instances of changing atrioventricular conduction, arrhythmias or less-than-constant RR intervals. Our object has been to develop a system for more nearly optimal noise reduction, to avoid the disadvantages of serial signal averaging, and to be able to record His-Purkinje activity in man on an every-beat basis. Using multiple parallel inputs wih linear amplification, additional logarithmic amplification, some bandpass filtering, and a logic circuit that ultimately examines and accepts or rejects a deflection as "true" signal, we can record, in most instances, on a beat-by-beat basis, this very valuable component of the cardiac electrical cycle.

Aortic cusp involvement causing severe aortic regurgitation in a case of relapsing polychondritis.

A case with relapsing polychondritis is described where primary involvement of the aortic valve cusps produced severe aortic regurgitation requiring valve replacement. An aneurysmal dilatation of the ascending aorta developing later led to disruption of the prosthesis requiring re-operation. Superior vena caval obstruction, an abdominal aortic aneurysm which ruptured and required resection, and obstructive lesions in common iliac arteries, presumably the result of the same process that involved the aorta and the cartilaginous structures, were also seen.

Evaluation of lead, zinc, and copper excretion in chronic moonshine drinkers.

To assess the usefulness of various routine and inexpensive tests widely used in the detection of an increased body lead load, the whole blood lead value, the 24-hour urinary excretion of lead, delta-aminolevulinic acid (DALA) and coproporphyrin, the presence of basophilic stippling and the whole blood osmotic fragility test were compared to a 24-hour urinary lead excretion after a calcium disodium edetate (EDTA) mobilization test in 20 chronic moonshine drinkers. Of these tests, only urinary lead excretion after EDTA mobilization was a sensitive indicator of excessive body burden, though a reference value of 650 micrograms urine lead excretion per 24 hours may have excluded some patients with increased lead loads. The reason for increased zinc and copper excretion before and after EDTA mobilization is not known but raises the possibility of their concomitant contamination of moonshine whiskey.

Effects of left anterior fascicular block on the depolarization process as depicted by total body surface mapping.

To examine the effects of left anterio fascicular block (LAFB) on the depolarization process as manifested on the body surface, 142 lead maps were recorded in 25 subjects with LAFB. Three abnormalities were detected: (1) In the early and mid portion of QRS, twenty of 25 subjects showed abnormal anterior superior positivity, starting in the precordial area and proceeding toward the left subclavicular area. The explanation was thought to be the relatively delayed, dysynchronous, and superiorly directed altered sequence of depolarization of the anterior left ventricle. (2) All the subjects showed left lower abnormal negativity. This was thought to represent the unopposed receding activation front after the left ventricular breakthrough posteroinferiorly and also the negative aspect of the abnormally directed superior positivity. (3) Eleven subjects showed abnormal negative potentials at the right lower chest. This was thought to represent the partially unopposed activation fronts of the right ventricular free wall seen after right ventricular epicardial breakthrough, because of the absence of the usually cancelling normal forces from the anterior portion of the left ventricle. Additionally, the surface manifestation of the septal depolarization was found to be indistinguishable from nornal. This study further enhances our understanding of the altered sequence of depolarization in LAFB, as manifested on the body surface instant-by-instant.

Irradiation-induced constrictive pericarditis requiring pericardiectomy during pregnancy.

Constrictive pericarditis is a rare but potentially life-threatening complication of pregnancy. This is a case report of irradiation-induced constrictive pericarditis requiring pericardiectomy during pregnancy. It is hoped that our team approach to this particular problem can serve as a model for the management of similar medical and surgical complications of pregnancy.

Body surface map patterns of altered depolarization and repolarization in right bundle branch block.

Surface maps from 14 patients with right bundle branch block were analyzed throughout depolarization and repolarization. The abnormalities in depolarization found in all the subjects were 1) epicardial breakthrough that was delayed and shifted to the left, and 2) development of right upper anterior positivity during the midportion of depolarization. In eight patients, this positivity manifested as multiple peaks, suggesting a fragmented spread of depolarization. We believe these findings result not only from the delayed engagement of the right ventricle by the conduction process, but also from its nonuniform and dyssynchronous spread. The recovery phase displayed five abnormal patterns: 1) simultaneous negativity on the right and positivity on the left of the midline in six patients; 2) only negativity on the right of the midline in four; 3) only positive potentials in the left upper chest in two; 4) only negative potentials on the left side of the midline in one; and 5) negative potentials spread diffusely over the precordium in one. The different degrees of this altered repolarization, we believe, depend upon the degrees of altered sequence of activation of the heart in addition to the changes produced by the underlying disease process.

Demonstration of abnormal proximal conduction system by His bundle electrocardiography in a patient with a single ventricle.

His bundle electrocardiography in a patient with a single ventricle and 2:1 block showed the block to be proximal to the His bundle. The sinus node recovery time was normal. In addition, there was suggested evidence of a functionally and/or structurally abnormal accessory pathway. The role of His bundle electrocardiography in a patient with a single ventricle in defining the function of various portions of the conduction system was thus demonstrated.

A study of the effects of nicotine in the intact dog and the propensity for arrhythmias.

This is a study of the effects of nicotine exposure in the intact dog on the propensity for arrhythmias. The mean effective and total refractory periods were prolonged after nicotine. The diastolic current threshold was increased after nicotine in every animal, yet the threshold for repetitive firing was decreased in four animals, all of which had individually prolonged relative refractory periods. We conclude that nicotine may increase the propensity for arrhythmias when an appropriately timed premature stimulus, of sufficient strength, encounters a ventricle with sufficient dispersion of refractoriness to allow re-entrant arrhythmias to be sustained.