Inadequate Response to Adenosine Infusion During Cardiac Stress Magnetic Resonance Imaging

Aim:To determine the factors associated with an inadequate response to adenosine infusion during cardiac stress magnetic resonance imaging (MRI). Study Design: It is a retrospective cohort study. Introduction: Stress cardiac MRI is a highly accurate and non?invasive method to diagnose coronary artery disease (CAD). Stress MRI is performed by inducing stress with adenosine infusion.There is an increase in systemic andmyocardial blood flow (MBF) with vasodilator agents. Capillaries are maximally dilated in a diseased artery and cannot sustain increased myocardial oxygen demand. It results in delayed delivery of contrast, which leads to an area of perfusion defect in the myocardium. These perfusion defects can be accurately seen by cardiovascular magnetic resonance (CMR) and help in the prognosis of patients. Methods: A retrospective study on patients subjected to cardiac stress MRI was conducted in a Tertiary Care Cardiac Center from January 2019 to January 2022. In total, 99 patients underwent adenosine stress perfusion cardiac MRI. All patients received an adenosine infusion of 140 mcg/kg/min for 2 min. Subsequently, the dosage was increased by 20 mcg/kg/min every 2 min to a maximum of 210 mcg/kg/min until an adequate stress response was achieved. Adequate stress was defined as two or more of the following criteria: 1) Increase in heart rate >/= 10 beats perminute. 2) Decrease in systolic blood pressure SBP by >/= 10mmHg Symptoms like chest discomfort, breathlessness, and headache. Patients who satisfied two or more of the above criteria were labeled as responders and the patients who did not satisfy the above criteria with the maximum dose of 210 mcg/kg/min of adenosine infusion were labeled as non?responders. Multivariable logistic regression analysis with forward and backward stepwise selection was used to identify predictors in non?responders. Basic demographic variables with P value </= 0.2 were examined for inclusion in the model. A P value </= 0.05 was considered significant. Results: Nine patients (9.1%) showed inadequate stress response to adenosine infusion even with a maximum dose of 210 mcg/kg/min. Multivariate logistic regression analysis showed that left ventricular end?diastolic volume (LVEDV) was a predictor of inadequate response to adenosine infusion. Conclusion: Inadequate stress response to adenosine occurred in 9.1% of subjects with an infusion of 140–210 ug/kg/min. LVEDV is an independent and strong predictor in non?responders.

Correlation between Coronary Angiography and Impedance Cardiography

Aims and Objectives: The aims of the study were to find out the correlation between coronary angiographic findings and hemodynamic parameters derived from impedance cardiography (ICG) and echo-Doppler study. Patients, Materials and Methods: A total of 200 patients of acute myocardial infarction having chest pain, ST elevation in two or more contiguous leads of electrocardiogram (ECG), biomarker positivity, echocardiographic evidence of regional wall motion abnormality (RWMA), and coronary angiographic evidence of coronary lesions were recruited. Subjects unwilling to participate, moribund, critically ill subjects, and patients with concomitant heart failure, arrhythmia, and valvular lesions were excluded from the study. GE™ Vivid 7 Dimension machine was used for ECG-gated echo-Doppler studies. The left ventricular ejection fraction (LVEF), stroke volume (SV), RWMA, diastolic function, etc., were observed. ICG measured LVEDV, LVESV, LVEF, and other parameters particularly amplitudes of the different waves. Coronary angiography (CAG) was done in the Cath Lab having “Siemens™ Axiom Artis Zee (floor)” equipment. Results and Analysis: Results-analysis revealed there is negative correlation (Pearson’s correlation coefficient, r = −0.8) between augmentation pressure and coronary angiographic stenosis percentage and P value is also significant (P = 0.034). Pulse pressure (PP) also is positively correlated (r = −0.78) with coronary angiographic stenosis percentage and P value is also significant (P = 0.027). There is a negative correlation (r = −0.259) between augmentation index (AIx) and coronary angiographic lesions and that is statistically significant (P = 0.03). Conclusion: There is a positive correlation between ICG -derived hemodynamic parameters and the percentage stenosis of coronary arteries. Rise of augmentation pressure and PP in the ICG waveform is associated with coronary artery disease severity. AIx is negatively correlated with severity of coronary arterial stenosis

Real-time three-dimensional echocardiographic left heart parameters in healthy indian adults

Objective Cardiac chamber dimensions are race and anthropometry dependent. We determined the age and gender specific 3-Dimensional echocardiographic (3DE) reference values for dimensions and function of left ventricle (LV) and left atrium (LA) in normal Indian adults. Methods This single center prospective study enrolled 133 adult Indians free of heart disease and/or hypertensions, subjecting them to 3DE measurements of left atrial (LA) & left ventricular (LV) volumes, function and left ventricular mass (LVM). The higher limits of normal cut-offs were determined for these parameters and their dependency on age, gender and anthropometry were analyzed. Results The body surface area (BSA) corrected higher limit cut-offs were: 59.37 ml/m2 for LV end diastolic volume (59.19 ml/m2 and 59.61 ml/m2 for men and women, respectively; P = NS); 23.48 ml/m2 for LV end systolic volume (23.27 ml/m2 and 23.11 ml/m2 for men and women, P = NS). Mean LVEF was 64.79% ± 7.26 (62.99% ± 6.51 and 67.05% ± 7.58 in men and women, P = NS). Men had higher LVM than women (119.79 g±23.95 vs. 103.26 g±23.76, P < 0.001), this difference disappeared after BSA indexing. The higher limit cut-offs for normal LA volumes were 20.49 ml for minimum volume (21.18 ml and 19.46 ml for men and women, P = NS) and 39.76 ml for maximum volume (39.60 ml and 40.03 ml in men and women, P = NS). The parameters were smaller compared to western populations but the differences attenuated after BSA indexing. Conclusions The study reports normal 3DE parameters of size and function of left heart chambers in Indians.

A Case of Ischemic Angina with Heart Failure due to Congenital Coronary Aterial Anomaly

Coronary artery fistula is an unusual anomaly in elderly patients that consists of a communication bet- ween one of the coronary arteries and other cardiac chambers or veins. It causes many cardiac compli- cations due to hemodynamic changes, and thus has recognized its clinical significance. It occurs usually in congenital origin, but also occurs secondarily in traumatic or neoplastic or artherosclerotic coronary diseases. Congenital coronary artery fistula is a very rare congenital anomaly that results in multiple hemodynamic complications. It has reported rarely in elderly patients, that induces myocardial ischemia due to coronary steal syndrome and heart failure that caused by diastolic volume overload via a left to left shunt. We observed a 68-year-old male patient with exertional chest pain and dyspnea, in whom selective coronary angiography revealed abnormal reticular communication between left anterior descending artery and left circumflex artery and drained to left ventricle through multiple microfistulous channels. We report this patient case who complicated by myocardial ischemia and left ventricular failure those caused by hemodynamic complication due to multiple coronary artery-left ventricular fistulae.

A Case of Ischemic Angina with Heart Failure due to Congenital Coronary Aterial Anomaly

Coronary artery fistula is an unusual anomaly in elderly patients that consists of a communication bet- ween one of the coronary arteries and other cardiac chambers or veins. It causes many cardiac compli- cations due to hemodynamic changes, and thus has recognized its clinical significance. It occurs usually in congenital origin, but also occurs secondarily in traumatic or neoplastic or artherosclerotic coronary diseases. Congenital coronary artery fistula is a very rare congenital anomaly that results in multiple hemodynamic complications. It has reported rarely in elderly patients, that induces myocardial ischemia due to coronary steal syndrome and heart failure that caused by diastolic volume overload via a left to left shunt. We observed a 68-year-old male patient with exertional chest pain and dyspnea, in whom selective coronary angiography revealed abnormal reticular communication between left anterior descending artery and left circumflex artery and drained to left ventricle through multiple microfistulous channels. We report this patient case who complicated by myocardial ischemia and left ventricular failure those caused by hemodynamic complication due to multiple coronary artery-left ventricular fistulae.