Quantification of low-dose dobutamine stress using speckle tracking echocardiography in coronary artery disease.

AIMS: We sought to evaluate the utility of speckle tracking echocardiography (STE) for detecting left ventricular (LV) mechanical abnormalities during low-dose (20 microg) dobutamine stress (DSE). METHODS AND RESULTS: Twenty-nine patients (56 +/- 12 years) with a history of recent acute coronary events (ACE) underwent STE-DSE. Left ventricular images, sampled at frame rates 70-100 Hz, were analysed off-line (Echopac BT 6.0.0). Velocity, strain, and rotational imaging were performed. Twenty patients had LV ejection fraction (EF) >40% (Group 1) whereas nine patients had LVEF <40% (Group 2). Average heart and frame rates were identical during DSE in the two groups (P = ns). Global circumferential strain (%) was significantly lower in Group 2 compared with Group 1 (10.65 +/- 5.30 vs. 16.82 +/- 6.61; P < 0.05) at rest and during peak stress (14.72 +/- 6.51 vs. 21.13 +/- 7.2; P < 0.05). The global peak rotation rate (degree/s) was, however, higher at rest in Group 2 (70 +/- 97 vs. 19 +/- 67; P < 0.05) and 20 microg stress. Peak systolic velocity increased in three of the four LV walls at 20 microg (in Groups 1 and 2). A global rotational rate increased significantly at 20 microg during systole in both the groups, but was unchanged in Group 2 during diastole. CONCLUSIONS: Speckle tracking echocardiography dobutamine stress appears to provide comprehensive information on LV mechanical status in the aftermath of ACE. The modality may help risk stratify such patients.

Microalbuminuria and left ventricular function in type 2 diabetes: a quantitative assessment by stress echocardiography in the Myocardial Doppler in Diabetes (MYDID) Study III.

BACKGROUND: Left ventricular (LV) function might be altered in type 2 diabetes (DM) and microalbuminuria (MA) may accentuate the abnormalities. We sought to investigate whether additional LV dysfunction could be unmasked using tissue Doppler (TVE)-enhanced dobutamine stress echocardiography (TVE-DSE) in patients with DM + MA. METHODS: Twenty seven DM subjects with MA, (DM + MA), 31 DM subjects without MA (DM - MA), and 13 Controls were evaluated using TVE-DSE. LV basal peak systolic (PSV), early (E') and late (A') diastolic velocities (cm/sec) at rest and peak stress were post-processed. LV filling pressure was assessed using E/E'ratio. RESULTS: PSV and E'velocity at peak stress in the respective three groups were 13.7 +/- 1.0, 10.1 +/- 1.1, 10.0 +/- 1.2 for PSV; and 10.0 +/- 1.6, 5.0 +/- 1.4, 4.8 +/- 1.4 for E' (p < 0.001 for controls vs. both groups). E/E' at rest was 7.9 +/- 0.7 in the controls, 10.8 +/- 2.4 in DM - MA, and 11.0 +/- 2.2 in DM + MA (p < 0.01 Controls vs. both the DM groups). CONCLUSIONS: Patients with DM + MA do not have additional LV regional systolic and diastolic dysfunctions compared with DM -MA, as revealed by TVE-DSE, when controlled for glycemia levels, lipids, and treatment strategies.

Acute administration of a single dose of valsartan improves left ventricular functions: a pilot study to assess the role of tissue velocity echocardiography in patients with systemic arterial hypertension in the TVE-valsartan study I.

BACKGROUND: The advent of colour-coded tissue velocity echocardiography (TVE) has now made it possible to quantify left ventricular (LV) functions in patients with systemic arterial hypertension (HTN). Hypothesis In this project, we have studied the cardiac effects of a single dose of orally administered valsartan in patients with known HTN. METHODS: Fifty-five patients with HTN with a mean age of 56 +/- 10 years were given an early morning dose of 80 mg valsartan withholding regular antihypertensive medications on the day of investigation. TVE images, acquired on VIVID systems were digitized for postprocessing of longitudinal and radial peak systolic velocities, strain rate, and systolic and diastolic time intervals before (pre) and 5 h after (post) administration of the drug. RESULTS: Blood pressure (mmHg) pre and post, respectively, were 147 +/- 15 versus 137 +/- 14 systolic and 90 +/- 7 versus 86 +/- 7 diastolic (all P<0.01). LV longitudinal systolic velocities (cm s(-1)) were significantly higher post in LV septum (5.7 +/- 1.1 versus 6.4 +/- 1.6; P<0.001) with similar results obtained in other LV walls. Radial strain rate (1 s(-1)) was significantly higher post compared with pre valsartan (2.1 +/- 0.6 versus 2.3 +/- 0.9; P<0.01). Regional diastolic filling and ejection times (ms) were significantly shorter post (390 +/- 122 versus 370 +/- 120 and 275 +/- 32 versus 163 +/- 36 respectively; all P<0.05). CONCLUSIONS: Within 5 h after oral administration of valsartan, improvement in regional myocardial systolic functions could be registered. Although the changes could well be secondary to afterload reduction, additional effects of the drug, evidenced by improved strain rate that is relatively load-independent, may have contributed in this improvement.

Impaired myocardial functional reserve in hypertension and diabetes mellitus without coronary artery disease: Searching for the possible link with congestive heart failure in the myocardial Doppler in diabetes (MYDID) study II.

BACKGROUND: Although the impact of type 2 diabetes mellitus (DM) and hypertension (HTN) on myocardial function has recently been studied using tissue Doppler echocardiography (TDE), the independent role of both conditions, and the influence of other risk factors on myocardial function has not been completely defined, particularly in absence of coronary artery disease (CAD). The aim of this study was to assess the myocardial functional reserve in patients with DM or HTN with apparently normal left ventricular (LV) systolic function. METHODS: Standard and dobutamine stress echocardiography using TDE was performed in 128 subjects: 59 had DM, 20 had HTN, 27 had both DM and HTN (HTN + DM), and 22 subjects were controls (C). Subjects with known CAD and depressed LV function were excluded. In addition, standard two-dimensional and Doppler measurements, LV regional peak systolic (PSV), early (E') and late (A') diastolic velocities, strain (S%) and strain rate (SR), were assessed at rest and peak stress. RESULTS: The LV mass did not differ, although relative wall thickness was significantly higher in subjects with HTN + DM and HTN. The PSV did not differ at rest but was lowest in subjects with HTN + DM at peak stress. The E' wave velocity was significantly lower in subjects with HTN + DM both at rest and during peak stress, as were S% and SR. CONCLUSIONS: The addition of DM to HTN has a negative effect on LV systolic and diastolic functions. A depressed myocardial functional reserve might be postulated as one of the pathophysiologic mechanisms for the excessive occurrence of congestive heart failure in patients with DM or HTN.

Indigenous recombinant streptokinase vs natural streptokinase in acute myocardial infarction patients: Phase III multicentric randomized double blind trial.

BACKGROUND: Streptokinase is the most widely used thrombolytic agent and can now be made using recombinant DNA technology. The present trial was initiated to assess an indigenous recombinant streptokinase (Shankinase, r-SK). AIM: To compare the efficacy and safety of indigenous recombinant streptokinase (Shankinase, r-SK) and natural streptokinase (Streptase, n-SK). SETTINGS AND DESIGN: Double blind, randomized, non-inferiority, multicentric, parallel study. MATERIALS AND METHODS: Patients of AMI < 6 hours of chest pain and 2 mm ST elevation in 2 contiguous chest leads V(1)-V(6) or 1 mm in limb leads were randomized to receive 1.5 miu of either r-SK or n-SK. CK Peaking and decrease of > or = 50% ST segment were used to assess reperfusion. STATISTICAL ANALYSIS: Difference in the groups was assessed by chi-square or paired t test as required. Probability value < 0.05 was considered significant with 95% confidence interval. RESULTS: Overall 150 patients were recruited (96 r-SK group and 54 in n-SK group) and demographic and clinical profile of the groups was comparable. Reperfusion was seen in 68.2% (58) and 69.4% (34) patients in r-SK and n-SK groups respectively. Commonly seen adverse events were fever in 7 (8.5%), hypotension in 3 (3.6%), nausea in 2 (2.4%) patients. Minor bleeding were seen in 4 (4.8%) of patients. CONCLUSION: Indigenous recombinant Streptokinase (r-SK) is as efficacious as natural streptokinase (n-SK) in establishing reperfusion as assessed by non-invasive parameters with comparable side effect profile.

Isolated type 2 diabetes mellitus causes myocardial dysfunction that becomes worse in the presence of cardiovascular diseases: results of the myocardial doppler in diabetes (MYDID) study 1.

AIMS: Patients with type 2 diabetes mellitus (DM) often suffer disproportionately and have a worse outcome when burdened with cardiovascular complications compared with those without DM. A specific heart muscle disease reportedly caused by DM per se may explain this. We sought to investigate whether an echo Doppler diagnosis of such a myocardial disease is clinically relevant in DM with or without coexistent coronary artery disease (CAD) and/or hypertension (HTN). SUBJECTS AND METHODS: Two hundred subjects (127 males, 73 females, 56 +/- 10 years) including controls (n = 23), patients with HTN (n = 20), CAD (n = 35), uncomplicated DM (n = 59), DM+HTN (n = 27), DM+CAD (n = 16) and DM+CAD+HTN (n = 20) underwent tissue Doppler-enhanced dobutamine stress echocardiography. Myocardial function was assessed by measuring left ventricular myocardial peak systolic velocity (PSV) and early diastolic velocity at rest and during peak stress, besides measurements of standard Doppler variables. RESULTS: Average left ventricular PSV at rest was significantly lower in CAD (4.7 +/- 1.5) compared with controls (5.7 +/- 1.2) and in DM+CAD+HTN (4.6 +/- 1.4) compared with DM (5.6 +/- 1.3; all p < 0.05). During peak stress, lower PSV persisted in CAD (9.5 +/- 3.1) and DM+CAD+HTN (8.1 +/- 2.7), while appearing de novo in DM (11.3 +/- 2.6) and HTN (11.0 +/- 2.3) unlike in the controls (12.5 +/- 2.5; all p < 0.001). When pooled together, DM subjects with CAD and/or HTN or both had significantly lower PSV (9.1 +/- 2.7) than those without (10.0 +/- 2.8; p < 0.001). Early diastolic velocity response was equally lower in both groups compared with the controls. CONCLUSION: The results suggest that dobutamine stress unmasks myocardial functional disturbances caused by uncomplicated DM. The discrete disturbances become quantitatively more pronounced in the presence of coexistent cardiovascular diseases.