William C. Roberts

Comparison of Total 12-Lead QRS Voltage in a Variety of Cardiac Conditions and Its Usefulness in Predicting Increased Cardiac Mass

Echocardiography provides a more accurate method to determine increased cardiac mass than does electrocardiography. Nevertheless, most offices of physicians do not possess echocardiographic machines, but many possess electrocardiographic machines. Many electrocardiographic criteria have been used to determine increased cardiac mass, but few of the criteria have been measured against cardiac weight determined at necropsy or after cardiac transplantation. Such was the purpose of the present study. Cardiac weight at necropsy or after transplantation was determined in 359 patients with 11 different cardiac conditions, and total 12-lead electrocardiographic QRS voltage (from the peak of the R wave to the nadir of either the Q or the S wave, whichever was deeper) was measured in each patient. Even in hearts with massively increased cardiac mass (>1,000 g), the total 12-lead QRS voltage was clearly increased (>175 mm) in only 94%, but this criterion was superior to that of previously described electrocardiographic criteria for left ventricular hypertrophy. Hearts with excessive adipose tissue infrequently had increased total 12-lead QRS voltage despite increased cardiac weight. Likewise, patients with fatal cardiac amyloidosis had hearts of increased weight but quite low total 12-lead QRS voltage. In conclusion, 12-lead QRS voltage is useful in predicting increased cardiac mass, but that predictability is dependent in part on the cause of the increased cardiac mass.

Isolated atrial amyloidosis and the importance of molecular classification.

Amyloid is identified microscopically as an amorphous extracellular hyaline material that exhibits “apple-green” birefringence with Congo red stains. Amyloid is not a chemically distinct entity, and currently available molecular methods are capable of identifying over 20 amyloidogenic precursor proteins. Some of the more common diseases associated with amyloidosis include plasma cell dyscrasias, chronic inflammatory disorders, hereditary-familial mutations involving transthyretin, Alzheimers disease, and so-called “senile” or age-related amyloidosis. The amyloid deposits in these various diseases may be isolated to a single organ such as the heart or brain, or the amyloidosis may be systemic. The senile types of cardiac amyloidosis can result from overproduction of atrial natriuretic factor or from accumulation of otherwise normal or wild-type transthyretin. We present the case of an 83-year-old hospitalized woman with known atrial fibrillation and previous pacemaker implantation who had cardiac arrest unresponsive to attempted resuscitation. Autopsy disclosed prominent amyloidosis involving the left atrium, and subsequent molecular studies identified the amyloidogenic material as alpha atrial natriuretic factor. Since the clinical management and genetic implications of the various diseases associated with amyloidosis are markedly different, we stress the importance of molecular classification whenever possible.

Profound left ventricular remodeling associated with LAMP2 cardiomyopathy.

Lysosome-associated membrane protein (LAMP2) cardiomyopathy is an X-linked and highly progressive myocardial storage disorder associated with diminished survival, which clinically resembles sarcomeric hypertrophic cardiomyopathy. As shown here in a young woman, the natural history of LAMP2 may demonstrate an extreme profile of left ventricular remodeling with regression of hypertrophy (i.e. marked wall thinning), chamber dilatation, and severe systolic dysfunction, all of which are associated with widespread transmural scarring.

The First Patient Clinically Diagnosed With Hypertrophic Cardiomyopathy

It has now been 50 years since the initial clinical description of hypertrophic cardiomyopathy. In this regard, it is noteworthy that the first patient diagnosed with this disease has survived to date in good health with an active and productive lifestyle -- albeit with heart transplantation necessitated by an aggressive disease course with progression to the end-stage phase.

Preoperative exclusion of significant coronary artery disease by 64-slice CT coronary angiography in a patient with a left atrial myxoma

A 49-year-old man without any significant past medical history presented to the emergency department with complaints of diploplia, paresthesias in both arms, vertigo, tinnitus in the right ear, and dysarthria. Physical examination was unremarkable. A computed tomographic (CT) scan of the head was normal. These symptoms resolved within several hours, consistent with a transient ischemic attack. Magnetic resonance imaging of the brain revealed acute infarcts in the left cerebellar hemisphere and in the right occipital lobe, suggesting a thromboembolic source. n nTransesophageal echocardiography disclosed a 2 × 2-cm mass attached to the left atrial aspect of the atrial septum, and surgical excision was planned. As the patient was considered to have a very low risk for the presence of significant arterial narrowing, he underwent a 64-slice cardiac CT scan rather than invasive coronary angiography. The scan demonstrated minimal plaque in the coronary arteries (Figure u200b(Figure11). The left atrial mass was also well visualized on both the axial slices and also with three-dimensional imaging (Figure 2a–c). Subsequently, the patients left atrial mass was excised without complication, and the mass was a typical myxoma (Figure 2d, e). This case demonstrates how, in the future, routine invasive coronary angiography may not be necessary as part of the workup for noncoronary cardiac surgery. In this instance, significant concomitant coronary artery disease was effectively excluded with multislice CT rather than an invasive procedure, thus allowing the surgery to proceed without a cardiac catheterization. In addition, CT imaging assisted with long-term prognostic information, as it suggested the need for the patient to be on cholesterol reduction therapy by demonstrating the early presence of coronary atherosclerosis. n n n nFigure 1 n nThree-dimensional reconstruction of the patients coronary arteries (3D) with multislice computed tomography. Curved reformat images of the left anterior descending (LAD) coronary artery, right coronary artery (RCA), and left circumflex coronary artery ... n n n n n nFigure 2 n n(a, b) Axial slices from the patients multislice computed tomographic scan demonstrating the myxoma attached to the left atrial aspect of the atrial septum (arrowheads). (c) The myxoma (arrowhead) shown via a “navigator” view inside the ...

Influence of Chronic Renal Failure on Cardiac Structure.

It has been long recognized that patients with end-stage renal disease (ESRD) have an approximate 10-fold increase in mortality compared to age-matched individuals in the general population [(1)][1]. Approximately one-half of this mortality is attributable to cardiovascular disease in the large

Distribution and Significance of Cardiac Muscle Cell Disorganization in the Left Ventricle of Patients with Hypertrophic Cardiomyopathy: Evidence of a Diffuse Cardiomyopathic Process *

The distribution of cardiac muscle cell disorganization in different regions of the left ventricular wall was studied quantitatively in 52 patients with hypertrophic cardiomyopathy. Cellular disorganization was both common and extensive (mean area of tissue section disorganized 35 ± 4%) in the ventricular septum and proved to be a highly specific and sensitive marker for hypertrophic cardiomyopathy. Disorganization was also substantial (24 ±3%) in the left ventricular free wall of these patients, although less marked than in the ventricular septum (P<0.05). Anterior left ventricular free wall disorganization was particularly extensive (32 ±4%) and did not differ significantly from that present in the ventricular septum.

Aortic valve replacement for stenosis with or without coronary artery bypass grafting after 2 previous isolated coronary artery bypass grafting operations

Aortic valve replacement following an earlier coronary artery bypass grafting (CABG) procedure is fairly common. When this situation occurs, the type of valve dysfunction is usually stenosis (with or without regurgitation), and whether it was missed at the time of the earlier CABG or developed subsequently is usually unclear. We attempted to determine the survival in patients who had had aortic valve replacement after 2 previous CABG procedures. We describe 12 patients who had aortic valve replacement for aortic stenosis; rather than one previous CABG operation, all had had 2 previous CABG procedures. Only one patient died in the early postoperative period after aortic valve replacement, and the remaining 11 were improved substantially: all have lived at least 11 months, and one is still alive at over 101 months after aortic valve replacement. Aortic valve replacement remains beneficial for most patients even after 2 previous CABG procedures.

Liver transplantation after coronary artery bypass grafting

Twelve patients are described who had liver transplantation after coronary artery bypass grafting (CABG). The liver disease in most of the patients was a consequence of hepatitis C resulting from blood transfusions at the time of CABG.

Frequency of Plaque Dislodgement and Embolization in Transradial vs Transfemoral Approaches for Left-Sided Cardiac Catheterization: Clinically Silent vs Clinically Apparent Embolism

Overview Among patients with atherosclerosis of the aorta and its branches, the quantity of plaque is always greater in the distal (abdominal) aorta than in the proximal (ascending) aorta.1 Indeed, except for its presence at the sinotubular junction, plaque is usually absent or nearly absent in the ascending portion, even when the wall of the abdominal aorta contains plaque in every square millimeter of its lining (Figure). If this were not the case, coronary bypass probably would have never become standard practice. Additionally, when the abdominal aortic wall contains considerable plaque, the quantity of plaque in the descending thoracic aorta is usually not as extensive as the plaque present in the abdominal aorta. The aortic isthmus (the portion of aorta just distal to the origin of the left subclavian artery) is a particularly vulnerable site for heavy atherosclerotic plaque. The exception to the principle that aortic atherosclerosis begins in the abdominal portion and progresses retrograde with near-sparing of the ascending portion is the aortic plaque distribution in patients with homozygous familial hypercholesterolemia.2 In that condition (which occurs in approximately 1 in 1 000 000 persons2), the ascending aorta contains the most plaque and the descending aorta the least. Rarely, the same holds true in patients with heterozygous familial hypercholesterolemia.