Margaret Knoll

Usefulness of color Doppler proximal isovelocity surface area method in quantitating valvular regurgitation.

To define the clinical utility of the color Doppler proximal isovelocity surface area (PISA) method for estimating regurgitant stroke volume (SV), 160 regurgitant lesions were evaluated in 104 patients with mitral (MR), aortic (AR), and tricuspid (TR) regurgitation. Regurgitant SV by PISA was calculated as 2 pi R2 x V x (time-velocity integral/peak flow velocity), where R is the radius corresponding to the first blue-red interface velocity of the maximal PISA during the cardiac cycle. The time-velocity integral and peak flow velocity from the continuous-wave Doppler recording of the regurgitant jet were used to correct PISA for phasic variations in regurgitant flow. Fifteen lesions were excluded because of difficulty in tracing the continuous-wave Doppler regurgitant curve. Among 145 remaining regurgitant lesions, PISA was measurable in 50 (78%) of 64 cases of MR and 24 (69%) of 35 cases of TR but in only 12 (26%) of 46 cases of AR (p < 0.001). Regurgitant SV by PISA correlated modestly well with jet area/atrial area in all atrioventricular valve lesions (MR: r = 0.55; TR: r = 0.65; p < 0.001). However, the correlation improved if only central jets were considered (MR: r = 0.70; TR; r = 0.75; p < 0.001). These findings are not unexpected because jet area/atrial area underestimates the true severity of regurgitation in cases of eccentric (wall-impinging) jets. PISA was detected in all severe cases of regurgitation but in only 64% of cases of mild MR, 45% of cases of mild TR, and 6% of cases of mild AR (p < 0.01). The color Doppler PISA method is clinically useful in estimating regurgitant SV in MR and TR, including mild cases, but is less useful in AR.

Diastolic blood pressure as a determinant of Doppler left ventricular filling indexes in normotensive adolescents.

Alterations in left ventricular filling can occur with aging and in patients with hypertension, ischemic heart disease, congestive and hypertrophic cardiomyopathy and congenital heart disease. This study examines the effects of blood pressure on left ventricular diastolic filling indexes measured by Doppler ultrasound technique in 47 young normotensive adolescents (mean age 13 years). Left ventricular filling was assessed by Doppler peak early and late diastolic transmitral flow velocities, early and late diastolic flow velocity integrals and early diastolic deceleration. Systolic blood pressure did not correlate with any of the Doppler filling indexes, although it was related to echocardiographic left ventricular mass (r = 0.44, p less than 0.005). Diastolic blood pressure did not correlate with left ventricular mass; however, it was inversely related to peak early diastolic flow velocity (r = -0.44, p less than 0.005), early diastolic flow velocity integral (r = -0.40, p less than 0.01) and early diastolic deceleration (r = -0.32, p less than 0.05). The ratio of late to early peak filling (A/E) was directly related to diastolic blood pressure (r = 0.48, p less than 0.001). Examination of electrocardiograms showed that there was a stronger correlation between A/E ratio and diastolic blood pressure (r = 0.63) in 22 subjects with bimodal P waves in lead V1 than in subjects with unimodal P waves (r = 0.45).(ABSTRACT TRUNCATED AT 250 WORDS)

Acute cocaine administration induces ventricular regional wall motion and ultrastructural abnormalities in an anesthetized rabbit model

Whether acute doses of cocaine can induce left ventricular (LV) regional wall motion abnormalities in animals with otherwise normal coronary arteries is unknown. We studied rabbits receiving constant cocaine infusions (group I: 0.025 to 1.5 mg/kg/min, n = 10), multiple cocaine boluses (group II: 3-5 mg/kg each bolus, n = 10), or saline (group III; n = 8). In group I rabbits, short-axis LV area and diameter increased by 15% to 40% at 60 minutes compared to baseline and to controls (p < 0.01), but percentage of global area fractional shortening was unchanged. Eight rabbits in each of groups I and II, but no controls, developed LV regional wall motion abnormalities as detected by echocardiography: 15 (7 hypokinesis and 8 akinesis or dyskinesis) in the anteroseptal and 2 (hypokinesis) in the posterior LV wall. Among rabbits showing LV wall motion abnormalities, anteroseptal fractional shortening and % area reduction averaged > 20% less (p = 0.03 for area reduction) at 30 minutes versus controls. Only 50% of group I or II rabbits with LV anteroseptal wall motion abnormalities had intraventricular conduction disturbances. Radioactive microsphere flow studies (n = 6) 1 minute after a 4 mg/kg cocaine bolus revealed an equivalent decrease (10% to 20%, average) in septal and LV free wall perfusion (p value not significant). Electron microscopy revealed myocardial cell contraction band necrosis in 3 and sarcoplasmic reticular edema in 7 of 10 cocaine rabbits (unrelated to dose). We conclude that acute cocaine administration in rabbits frequently produces LV anteroseptal wall motion abnormalities even in the absence of differentially decreased perfusion or intraventricular conduction disturbances and produces ultrastructural abnormalities of the myocytes. These findings suggest a direct, nonuniform effect of cocaine on the LV myocardium.

Multiskilling and Multicredentialing of the Health Professional: Role of the Cardiac Sonographer

The American Society of Echocardiography (ASE) recognizes that cardiac sonographers are frequently multiskilled and multicredentialed. It is the position of the ASE that, above all, persons who perform cardiac ultrasonography should be fully trained and credentialed in cardiac sonography. If a person is multiskilled (practices another health-related discipline), he or she should be appropriately trained and credentialed in that discipline as well. Possession of multiple credentials provides some evidence that the person has met specific minimum competencies in those areas.This position supports effective, efficient, and high-quality patient care.

Innominate artery aneurysm with thrombus: Detection by two-dimensional echocardiography

A 51 year old man with an innominate artery aneurysm presented with claudication and ischemia of the right forearm and hand. Two-dimensional echocardiography visualized the saccular aneurysm and a pedunculated mobile thrombus within it that were not seen during aortic arch angiography. Two-dimensional echocardiography, shown to be useful in identifying intracardiac masses and aortic aneurysms, may be important in selecting patients with increased risk of embolization.

Antiarrhythmic efficacy of Ethmozine (moricizine HCl) compared with disopyramide and propranolol.

In the investigation of new antiarrhythmic drugs, comparative trials with clinically available antiarrhythmic agents provide a perspective from which to judge the new investigational agent. Two clinical investigations of moricizine HCl, each using a placebo-controlled, double-blind, crossover design, are summarized. In the first study, 18 patients with greater than or equal to 30 ventricular premature complexes (VPCs) per hour (mean 369 +/- 95) were given propranolol (120 mg daily) compared with moricizine HCl (816 +/- 103 mg daily). Propranolol suppressed 38% of VPCs in the study group, moricizine HCl, 81% of VPCs, and the combination of both drugs, 87%. Moricizine HCl was more effective than propranolol in suppressing VPCs at all individual levels greater than 70% (p less than 0.05, McNemars test). The combination of moricizine HCl and propranolol was well tolerated. The second investigation used a placebo-controlled, double-blind, crossover design to compare the efficacy of disopyramide (600 mg daily) and moricizine HCl (800 mg daily) in 27 patients. Patients had greater than or equal to 40 VPCs/hr on a 24-hour ambulatory electrocardiogram. During moricizine HCl administration, the mean VPC frequency decreased from 524 to 151 VPCs/hr (71.2% reduction). In contrast, disopyramide reduced VPC frequency from 535 to 253 VPCs/hr (52.8% reduction) and demonstrated significantly greater side effects (p less than 0.05). Moricizine HCl was more effective than disopyramide in suppressing VPCs at all individual percent reduction levels greater than 70% (p less than 0.05, McNemars test). Moricizine HCl was more effective in suppressing VPCs than either disopyramide or propranolol, with significantly fewer side effects.