Detection of severe left anterior descending coronary artery stenosis by transthoracic evaluation of resting coronary flow velocity dynamics

Non Invasive Detection of Coronary Sinus Flow Changes Over Time After CABG

Background

Coronary New blood in the vascular bed after Coronary Artery Bypass Grafting (CABG) may represent a turning point between ischemia and normal tissue nutrition. Its quantification can help to better understand coronary artery hemodynamics after revascularization.

Objective

Quantification of coronary sinus blood flow changes over time after Coronary Artery Bypass Grafting (CABG) using Transthoracic Echocardiography (TTE).

Methods

Prospective basic research, with repeated measurements on hospital sample of 61 patients whom CABG was conducted. We performed TTE recordings to measure CS flow before and two times after CABG (1 and 6 postoperative day). We measure CS diameter, Velocity Time Integral (VTI) and systemic hemodynamic data. Data needed for LV mass calculation were recorded once. During statistical analysis we define: α = 0,01, β = 0,01 (power = 1-β β= 0,99), Sample size = 60, Effect size= 0,68. We used ANOVA for Repeated Measures as main statistical test in SPSS.

Results

Preoperatively we found low overall CS flow of 181 ±72 ml/min (0,68 ±0,30 ml/gram-LV/min). After surgery there was constant increase of CS flow from 276 ±79 ml/min (1,13 ±0,35 ml/gram-LV/min) first postoperative day, to 355 (±99) ml/min (1,30 ±0,46 ml/gram-LV/min) sixth postoperative day.

Discussion

Amount of new blood was statistically significant after CABG with P<0,001. Same result was found after classifying patients per number of graft received, with the highest amount of new blood after four bypasses. Amount of new blood was not different if patient gets two or three bypasses.

Conclusion

There was significantly new amount of blood in coronary bed after CABG, with constant increase over first 6 days.

Traumatic Takotsubo Cardiomyopathy in a Patient with Extensive Coronary Artery Disease

Takotsubo Cardiomyopathy (TCM) should be considered in the differential diagnosis for patients with cardiovascular symptoms not only following emotional trauma but also following motor vehicle accidents. A 45-year-old woman presented with chest pain following a motor vehicle accident. While she had an elevated troponin level and an extensive history of cardiac disease, her electrocardiogram was normal. Echocardiogram, however, demonstrated transiently reduced left ventricular systolic function with mid to apical hypokinesis consistent with TCM. We emphasize the use of a diagnostic score and point of care focused cardiac ultrasound (FOCUS) to expedite the recognition, evaluation, and treatment of suspected TCM in an Emergency Department setting.

Differences in coronary artery blood velocities in the setting of normal coronary angiography and normal stress echocardiography

Background

Normal left anterior descending (LAD) coronary artery as determined by coronary angiography is considered not only to reflect normal angiography but also to correlate with normal anatomy and function. However, subjects who undergo coronary angiography may differ from those who do not need to have invasive evaluation even if their functional noninvasive studies like dobutamine stress echocardiography (DSE) were normal.

Aim

LAD velocities in subjects with normal angiography and those with normal DSE are equal.

Methods

A total of 244 subjects were evaluated, 78 had normal LAD by angiography and 166 had normal LAD by DSE. All had Doppler sampling of LAD velocities by transthoracic echocardiography.

Results

Velocity was higher in the angiographic subgroup in diastole 41 ± 23 vs 33 ± 14 cm/s, p = 0.0078; systole 18 ± 14 vs 13 ± 7 cm/s, p = 0.012; diastolic integral 12.6 ± 5 vs 9.8 ± 3.8 cm, p = 3.15 × 10^-5; systolic velocity integral 4 ± 2.9 vs 2.8 ± 1.9, p = 0.0014. While heart rate was similar in both groups, the product of diastolic velocity integral and heart rate of the LAD in the angiographic group was higher: 902 ± 450 vs 656 ± 394, p = 0.00599. Diastolic velocity deceleration time was similar in both groups. Coronary flow reserve defined as diastolic velocity ratio before and immediately after DSE correlated negatively with baseline velocity, r = -0.4.

Conclusions

Mode of defining normality of coronary artery affects velocity behavior of the vessel, reflecting functional differences possibly related to microvasculature and vasodilatation.