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Biomedical subjects

C M Gross

Publications and source records attributed to C M Gross.

At least 37 records · Page 2Linked to original sources

Assessment of late potentials in patients with essential hypertension by the signal-averaged electrocardiogram with five year follow-up.

Both the Framingham and Manitoba Heart Studies have identified electrocardiographic left ventricular (LV) hypertrophy (LVH) as a risk factor for sudden cardiac death. Low amplitude ventricular late potentials in the terminal part of ventricular activation have been associated with sustained ventricular tachycardia and have identified those at risk for sudden cardiac death. Therefore, we prospectively examined 23 essential hypertensives without known symptomatic coronary heart disease by two-dimensional echocardiography and signal averaged electrocardiograms (SAECGs) for the detection of ventricular late potentials. The SAECG vector-magnitude complex measurements included the total duration of the complex (QRSd), the voltage in the last 40 ms (V40), and the duration of low amplitude signals < 40 microV in the terminal portion of the complex (LASd). Echocardiographic parameter means were: LV diastolic diameter = 46.0 +/- 4.5 mm, combined septal and posterior wall thickness = 23.3 +/- 4.2 mm, LV mass (Woythaler method) = 235.1 +/- 69.1 g, LV mass (Penn method) = 199.5 +/- 55.3 g and ejection fraction = 63.9 +/- 6.2%. SAECG measurement means were QRSd = 88.2 +/- 9.9 ms, V40 = 63.1 +/- 34.7 microV RMS, and LASd = 23.5 +/- 10.0 ms. No echocardiographic parameter correlated with SAECG duration; however, age correlated with QRSd (r = 0.48, P = 0.02). Posterior wall thickness (r = -0.43, P = 0.04), LV mass index (r = -0.44, P = 0.03) and LV mass/height (r = -0.49, P = 0.02) inversely correlated with LASd.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

First clinical experiences with a new angioscopic system for diagnosing peripheral vascular changes.

Conventional angiography allows a global view of regional vascular anatomy but precise information can only be deduced indirectly using contrast medium. The use of the three-dimensional picture of angioscopy, however, allows a direct evaluation of the vascular system. In order to extend our experiences with angioscopy, we employed a new micro-cardio-angioscopic system which consists of four components: a CCD color camera (360,000 pixels); a highly flexible optical probe which can be resterilised (1.4-0.6 mm diameter) incorporating 10,600-6,000 glass fibers, with a viewing angle of 140 degrees, 70 degrees, and 50 degrees and a focusing system that allows a distance from 2 mm to infinity; a high power light source and an insertion catheter with inflatable balloon. Using a known technique (intermittent blood-flow blockage and continual rinsing with NaCl solution), 36 cases involving 27 patients were examined before and after desobliteration of the femoral artery. In 88% of the cases it was possible to control the result of the intervention by angioscopy. Smaller intimal lips, the thrombotic wall, and intimal ruptures were clearly visible. Quantification of the stenoses was also successful in 88% of the cases, and in 8 patients the angioscopic findings deviated from the conventional angiogram. In 14% of the cases, angioscopic examination of the recanalisation result showed that thrombolytic therapy was necessary. Angioscopy offers the possibility of qualitative vascular diagnosis. It is a valuable addition to angiography.

Angioplasty, Laser↗

Case report: acute presentation of pseudo myocardial infarction secondary to metastatic cancer.

Electrocardiographic ST segment changes that mimic myocardial infarction (MI) may occur secondary to metastatic carcinoma. Presented here is a case in which symptomatology suggestive of acute MI occurred with impressive new anterior ST segment elevation in a patient with a history of laryngeal carcinoma. Clinical options in this setting are discussed, including use of thrombolytic agents and acute catheterization.

Carcinoma, Squamous Cell↗

Long-term severe pulmonary hypertension associated with right atrial myxoma.

An 18-year-old black woman presented with marginally compensated right heart failure, severe pulmonary hypertension, tricuspid incompetence, and right atrial myxoma. Catheterization suggested a substantial reactive component to her P-HTN, especially to nifedipine. Initial management consisted of excision of two right atrial myxomas and tricuspid annuloplasty, and postdischarge management with nifedipine, 30 mg four times daily. Emergency pulmonary thromboendarterectomy was required two weeks later for acute cor pulmonale. It is suggested that concomitant procedures are mandatory in this setting because of the otherwise accelerated adverse pathophysiology of obliterative pulmonary vascular obstructive disease.

Adolescent↗

Abnormal left ventricular-left atrial posterior wall contour: a new two-dimensional echocardiographic sign in constrictive pericarditis.

We measured the angle P formed by the junction of the left ventricular and left atrial posterior walls, and also the distances from the ultrasound transducer to the left ventricular posterior wall and left atrial posterior wall (DV and DA), respectively, in the parasternal long-axis two-dimensional echocardiographic view. We studied 23 normal adults and four patient groups with conditions commonly associated with left atrial dilatation: mitral regurgitation (14), mitral stenosis (16), hypertrophic cardiomyopathy (13), and constrictive pericarditis (7). Statistically significant differences were found between the constrictive pericarditis group and each of the other groups. Angle P was less than 150 degrees in 0 of 23 normal individuals, in 0 of 14 with mitral regurgitation, in 1 of 16 with mitral stenosis, in 0 of 13 with hypertrophic cardiomyopathy, and in five of seven with constrictive pericarditis. DA minus DV exceeded 20 mm in 0 of 23 normal individuals, one of four with mitral regurgitation, in 6 of 16 with mitral stenosis, in 0 of 13 with hypertrophic cardiomyopathy, and in five of seven patients with constrictive pericarditis; We conclude that angle P greater than 150 degrees suggests constrictive pericarditis; DA minus DV greater than 20 mm suggests constrictive pericarditis if mitral stenosis can be excluded.

Echocardiography↗

Echocardiographic detection of an infected superior vena caval thrombus presenting as a right atrial mass.

A patient was found to have a large mobile right atrial mass by two-dimensional echocardiography after developing sepsis due to prolonged central hyperalimentation. Contrast echocardiography was helpful in localizing the origin of the mass. A large infected thrombus emanating from the superior vena cava was removed at operation. The discussion includes a review of the literature on the echocardiography of right atrial masses.

Catheterization, Central Venous↗

Congenital absence of pericardium: an unusual cause of atypical angina.

Congenital defects of the pericardium are unusual. Patients may experience exertional chest pain, cardiac arrhythmias, syncope, sudden death, or incarceration of myocardium, or they may be entirely asymptomatic. We describe the case of a symptomatic pericardial herniation diagnosed by echocardiography and confirmed by cineangiography. Successful repair was accomplished using a polytetrafluoroethylene soft-tissue prosthesis.

Adult↗

Right atrial thrombus formation following central venous dialysis catheter placement.

Silicone rubber central venous dialysis catheters are used to provide vascular access in acute renal failure patients and in chronic dialysis patients in whom conventional vascular access cannot be achieved or maintained. The use of these catheters is not without hazard. The first reported case of right atrial thrombus formation associated with the use of a double lumen silicone rubber central hemodialysis catheter is described. This patient's course points out another potential complication of this type of vascular access and emphasizes the importance of removing such catheters in a timely fashion when they are no longer required for dialysis.

Catheterization, Central Venous↗

Diagnostic precision of echocardiography in mitral valve prolapse.

In order to determine the precision with which currently used echocardiographic criteria can be applied for the diagnosis of mitral valve prolapse, three independent observers (A, B, and C) blindly analyzed the separate M-mode and two-dimensional echocardiograms of 50 patients, 27 of whom had previously been identified clinically as having echocardiographic evidence of prolapse. Observer A's intraobserver repeatability for M-mode echocardiography was 92%, Observer B's was 84%, and Observer C's was 90%. For two-dimensional echocardiography, Observer A's intraobserver repeatability was 98%, Observer B's was 80%, and Observer C's was 82%. We believe that the variability in intraobserver repeatability is related to the frequency with which individual observers diagnosed prolapse. The interobserver repeatability for M-mode echocardiography for Observer A versus B was 64%, for Observer A versus C it was 80%, and for Observer B versus C it was 66%. The interobserver repeatability for two-dimensional echocardiography for Observer A versus B was 54%, for Observer A versus C it was 70%, and for Observer B versus C it was 52%. There was no significant difference between the inter- and intraobserver variability of M-mode versus two-dimensional echocardiography. Review of cases in which readings were discrepant revealed that these cases usually had relatively mild changes. Clinicians should be aware of the inherent variability of echocardiographic interpretation when they make a diagnosis of mitral valve prolapse.

Echocardiography↗

The relative merits of pulsus paradoxus and right ventricular diastolic collapse in the early detection of cardiac tamponade: an experimental echocardiographic study.

An inspiratory decline in systolic arterial blood pressure exceeding 10 mm Hg has been used clinically to identify hemodynamically significant pericardial effusions. Recently, the echocardiographic sign of right ventricular diastolic collapse (RVDC) has been shown to occur early in the course of cardiac tamponade in association with a hemodynamically important decline in cardiac output. This study was undertaken to compare the relative merits of pulsus paradoxus and the onset of RVDC in the early detection of cardiac tamponade in an unanesthetized canine preparation. We studied six chronically instrumented, conscious dogs with two-dimensional echocardiography during cardiac tamponade induced by continuous infusion of saline into the pericardial space. We recorded intrapericardial pressure, cardiac output (electromagnetic flowmeter), aortic (catheter-tip transducer) and right atrial blood pressures, heart rate, and respiration. None of the dogs had RVDC when the pericardial space was empty, but all dogs showed RVDC during cardiac tamponade. We found that RVDC was strongly related to all of the cardiac parameters evaluated (intrapericardial pressure, cardiac output, aortic blood pressure, heart rate, and stroke volume) and provided information on each that was independent of that provided by pulsus paradoxus. Furthermore, RVDC appeared to be more strongly related to most cardiac parameters than was pulsus paradoxus and to be more sensitive and specific than pulsus paradoxus in detecting changes in intrapericardial pressure early in cardiac tamponade.

Animals↗