Chalapathirao Gudipati

Echocardiographic evaluation of cardiac structure and function in elderly subjects with isolated systolic hypertension

One hundred four participants in the Systolic Hypertension in the Elderly Program (SHEP) trial (mean age 71 +/- 6 years) were examined by Doppler echocardiography to gain information on the cardiac structural and functional alterations in isolated systolic hypertension. Participants had a systolic blood pressure greater than 160 mm Hg with diastolic blood pressure less than 90 mm Hg and were compared with 55 age-matched normotensive control subjects. Left ventricular mass index was significantly higher in the participants than in the normotensive subjects (103 +/- 28 versus 87 +/- 23 g/m2, p = 0.0014) and 26% of the participants met echocardiographic criteria for left ventricular hypertrophy compared with 10% of normotensive subjects. Left atrial index was also greater in participants than in normotensive subjects (2.26 +/- 0.32 versus 2.11 +/- 0.24 cm/m2, p = 0.005) and 51% of participants had left atrial enlargement. Doppler measures of diastolic filling were significantly different between the two groups, with peak atrial velocity higher (76 +/- 17 versus 69 +/- 17 cm/s, p = 0.02) and ratio of peak early to atrial velocity lower (0.76 +/- 0.23 versus 0.86 +/- 0.22, p = 0.0124) in participants. There was no correlation between left ventricular mass index and Doppler measures of diastolic function, but relative wall thickness correlated significantly with peak atrial velocity (r = 0.22, p = 0.016) and peak early to peak atrial velocity ratio (r = 0.24, p = 0.007). There was no difference in M-mode ejection phase indexes of systolic performance (shortening fraction and peak velocity of circumferential fiber shortening) between the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

EFFECTS OF AGING ON LEFT VENTRICULAR STRUCTURE AND FUNCTION

To better characterize the cardiac structural and functional changes that are associated with aging, Doppler-echocardiography was performed on 23 young (mean age, 25 years) and 30 old (mean age, 70 years) healthy normotensive subjects. Left ventricular cavity dimensions and wall thickness were determined and left ventricular mass index was calculated from M-mode echocardiograms. Stroke volume was calculated from Doppler-measured aortic flow. Diastolic filling was evaluated by pulsed Doppler echocardiography of mitral inflow. Posterior wall thickness (1.0 vs 0.8 cm, p less than 0.05) and relative wall thickness (0.42 vs 0.35, p less than .05) were significantly greater in the elderly subjects compared with the younger subjects. Left ventricular mass index increased on average 0.25 gm/m2/yr but was not significantly increased in the elderly compared with the younger subjects (89 vs 77 gm/m2). Shortening fraction and stroke volume did not differ between the two groups. Diastolic filling was dramatically altered with aging, and the elderly subjects demonstrated a doubling of percent atrial contribution (37% vs 19%, p less than 0.0001) and halving of peak early-to-peak atrial velocity ratio (0.85 vs 1.77, p less than .01).

Systolic and diastolic flow abnormalities in elderly patients with hypertensive hypertrophic cardiomyopathy

Seventeen patients with clinical and echocardiographic features of hypertensive hypertrophic cardiomyopathy of the elderly were studied to more completely characterize left ventricular systolic and diastolic function in this group. Measurements of left ventricular structure and systolic and diastolic function were made in the study patients and compared with those of age-matched control subjects. The study group had significantly greater left ventricular mass, wall thickness, shortening fraction and relative wall thickness than did the control subjects. Left ventricular end-diastolic dimension was smaller and left atrial size was not different in study patients compared with control subjects. Left ventricular filling was characterized by an increased peak atrial velocity and reduced ratio of peak early to peak atrial velocity in the study group. Left ventricular outflow velocities were elevated in 14 of the 17 study patients with peak velocities ranging from 1.2 to 5.0 m/s corresponding to a peak intraventricular gradient of 16 to 100 mm Hg. The velocity waveforms in these patients were late-peaking, similar to those described in hypertrophic obstructive cardiomyopathy. The elevated velocities were localized to the left ventricular outflow tract. These findings imply a pathophysiologic state in these elderly patients with long-standing hypertension, very similar to that in hypertrophic obstructive cardiomyopathy, and provide further support for the use of pharmacologic agents with negative inotropic properties or positive lusitropic properties in this group.

Effect of abruptly increased intrathoracic pressure on coronary blood flow velocity in patients

To assess the effects of abruptly increased intrathoracic pressure on coronary blood flow, arterial pressure, heart rate, and intracoronary Doppler blood flow velocity were measured continuously during cough(s) and again during the four phases of the Valsalva maneuver in 14 patients. Coughing significantly increased the systolic pressure (137 +/- 25 to 176 +/- 30 mm Hg), diastolic pressure (72 +/- 10 to 84 +/- 18 mm Hg), and arterial pulse pressure (65 +/- 27 to 92 +/- 35 mm Hg), with no change in heart rate. The mean coronary flow velocity decreased (17 +/- 10 to 14 +/- 12 cm/sec, p less than 0.03). During the Valsalva maneuver, despite marked reduction in the mean arterial pressure during phase III (96 +/- 12 to 68 +/- 14 mm Hg, p less than 0.05), the reduction of coronary blood flow velocity did not achieve statistical significance. These data demonstrate that neither type of abrupt physiologic increase in intrathoracic pressure enhances coronary blood flow. Coughing does not improve coronary perfusion pressures or flow velocity, despite marked increases in arterial diastolic pressure. The Valsalva maneuver, for the most part, does not significantly alter coronary blood flow velocity.

Effects of pharmacologic coronary hyperemia on echocardiographic left ventricular function in patients with single vessel coronary artery disease

To assess whether pharmacologic coronary vasodilation could provoke new left ventricular wall motion abnormalities in patients with single vessel coronary artery disease, systemic hemodynamics, coronary blood flow velocity and left ventricular wall motion were measured by two-dimensional echocardiography during administration of 10 mg of intracoronary papaverine in 14 patients before and again immediately after left coronary angioplasty (group 1). As a comparison with an intravenous method, left ventricular wall motion was analyzed after 0.56 mg/kg body weight of intravenous dipyridamole in a separate group of 13 patients with single vessel coronary disease (group 2). Heart rate-blood pressure product increased 3% to 6% in papaverine-treated patients and 14 +/- 11% (p = NS) in dipyridamole-treated patients. No angiographic collateral vessels were present in either group. Although intracoronary mean flow velocity measured in the 14 group 1 patients and in 5 normal control subjects during papaverine treatment increased from 125% to 400% of basal flow velocity, papaverine induced new left ventricular wall motion abnormalities in only 5 of the 14 patients before coronary angioplasty. In three of five patients, left ventricular wall motion abnormalities persisted after successful coronary angioplasty. Four of the 14 patients demonstrated augmentation of left ventricular wall motion with papaverine. After intravenous dipyridamole, only 3 of the 13 group 2 patients developed new left ventricular regional asynergy. These data suggest that selective (papaverine) and, most likely, global (dipyridamole) augmentation of coronary flow alone does not reliably identify potential ischemic left ventricular regions affected by critical single vessel coronary artery disease.

Immediate and short-term effects of aortic balloon valvuloplasty on left ventricular diastolic function and filling in humans

The effect of aortic balloon valvuloplasty on left ventricular diastolic function and filling was investigated in 44 adult patients with severe aortic stenosis. Two-dimensional and Doppler echocardiography was performed in all patients before and 24 h after valvuloplasty. In 19 patients (short-term group) repeat studies were performed at 3 (n = 2) and 6 (n = 17) months. Left ventricular relaxation, chamber stiffness and filling were assessed in 16 patients (immediate post-valvuloplasty group) before and immediately after valvuloplasty by simultaneous micromanometer left ventricular pressure tracings and echocardiograms. Immediately after valvuloplasty, relaxation was slightly impaired in the immediate post-valvuloplasty group, as reflected by the isovolumic relaxation time constant (56 +/- 26 to 68 +/- 39 ms; p less than 0.01) and maximal negative dP/dt (2,063 +/- 640 to 1,767 +/- 495 mm Hg/s; p less than 0.001). The chamber stiffness constants and diastolic filling dynamics were unchanged immediately after valvuloplasty. Twenty-four hours after valvuloplasty, patients without mitral regurgitation (n = 24) showed increases in the peak early filling velocity (72 +/- 31 to 83 +/- 28 cm/s; p less than 0.05) and peak early to atrial filling velocity ratio (0.8 +/- 0.6 to 1.0 +/- 0.7; p less than 0.05). However, in patients with mitral regurgitation (n = 20), the diastolic filling dynamics were not significantly changed. In the short-term group at the 3 to 6 month follow-up period, patients without mitral regurgitation (n = 12) showed striking increases compared with pre-valvuloplasty values in the peak early filling velocity (66 +/- 21 to 93 +/- 31 cm/s; p less than 0.02), peak early to atrial filling velocity ratio (0.6 +/- 0.2 to 0.9 +/- 0.4; p less than 0.02) and early time-velocity integral (9 +/- 4 to 16 +/- 6 cm; p less than 0.002). In patients with mitral regurgitation (n = 7) decreases occurred in the peak early filling velocity (123 +/- 32 to 106 +/- 28 cm/s; p less than 0.05) and peak early to atrial filling velocity ratio (1.5 +/- 0.7 to 1.1 +/- 0.6; p less than 0.05). Functional class in hospital improved after valvuloplasty (3.1 +/- 1.0 to 2.6 +/- 0.9; p less than 0.001) and correlated modestly with the percent decrease in Doppler-derived peak gradient (rs = 0.41, p less than 0.02) and mean gradient (rs = 0.36, p less than 0.05), but did not correlate with changes in aortic valve area, left ventricular ejection fraction or diastolic filling variables.(ABSTRACT TRUNCATED AT 400 WORDS)

Effects of left ventricular hypertrophy on the signal-averaged electrocardiogram

Abstract Signal-averaged electrocardiography (SAECG) has made possible the identification of late potentials in patients at risk of developing malignant ventricular arrhythmias. 1–9 Late potentials have been shown to predict sudden cardiac death, 3,4 clinical ventricular tachycardia, 1,3–6 and ventricular tachycardia that is inducible with programmed electrical stimulation. 8–10 Sudden cardiac death 11,12 and ventricular arrhythmias 13–19 are more prevalent in patients with echocardiographic left ventricular (LV) hypertrophy. Late potentials might be useful in identifying a subgroup of patients with LV hypertrophy who are at high risk to experience clinical ventricular tachycardia or sudden cardiac death. However, patients with LV hypertrophy may have intraventricular conduction disturbances and repolarization abnormalities that may interfere with the ability of SAECG to accurately detect late potentials. To evaluate the use of SAECG in patients with LV hypertrophy, we examined 58 patients with SAECG, echocardiography and programmed electrical stimulation. In this study, we compare the clinical characteristics, SAECG findings and electrophysiology results of a group of patients with echocardiographic LV hypertrophy to a group of patients without echocardiographic LV hypertrophy.

The effects of high (sodium meglumine diatrizoate, Renografin-76) and low osmolar (sodium meglumine ioxaglate, Hexabrix) radiographic contrast media on diastolic function during left ventriculography in patients

Although a majority of studies indicate superior hemodynamic and clinical profiles of low osmolar compared with high osmolar contrast media, the effect of these agents on diastolic left ventricular function has not been examined. We prospectively examined hemodynamic, electrocardiographic, and echocardiographic indices of left ventricular function in patients undergoing contrast ventriculography with a high osmolar, ionic, monomeric contrast, diatrizoate (Renografin-76) compared with a low osmolar, ionic, dimeric contrast, ioxaglate (Hexabrix). Thirty patients were randomized to each group. There were no clinical differences between the two groups. The decrease in systemic pressures was significantly greater with diatrizoate after left ventriculography (-38.5 +/- 3.5 versus -18.2 +/- 2.3, p less than 0.001) and selective left coronary angiography (-29.5 +/- 2.4 versus -17.4 +/- 2.6, p less than 0.001). In addition, left ventricular end-diastolic pressure increased significantly more with diatrizoate (7.3 +/- 0.9 versus 2.7 +/- 0.8 mm Hg for ioxaglate, p less than 0.001). QT interval prolongation occurred in both patient groups. Diatrizoate decreased systemic vascular resistance, and increased cardiac output and left ventricular ejection fraction more than ioxaglate, while simultaneously increasing left ventricular end-diastolic volume and altering the peak atrial filling velocity. Negative dp/dt (p less than 0.05), but not Tau, computed by the logarithmic or derivative methods, was reduced by diatrizoate. These data indicate that significant alteration of diastolic filling patterns occurs with high osmolar compared with low osmolar contrast agents. Although the clinical significance of this observation is currently unknown, these data further support the reported hemodynamic superiority of the low osmolar, dimeric contrast agent ioxaglate during contrast angiography.

Paraverine-induced chest pain due to coronary vascular steal: Demonstration wtih angiographic and intracoronary flow velocity measurements

We observed a patient who developed typical ischemia chest pain during administration of intracoronary papaverine to measure coronary vasodilatory reserve. Coronary collateral steal was documented by angiography and was reserved with intracoronary nitroglycerin