Electrocardiography Predictive Value on Coronary Slow Flow Phenomenon

Coronary Slow Flow Phenomenon (CSFP) is characterized by the slow flow of contrast in one or more epicardial coronary vessels without evidence of coronary artery stenosis during coronary angiography procedures. CSFP is fairly common at the time of elective angiography with an incidence of around 7% and accounts for about 4% of hospitalized unstable angina cases. Coronary angiography is currently still the only effective way to detect CSFP, but this procedure is an invasive procedure with high costs, there is a risk of allergy to contrast. Electrocardiography (ECG), as a widely available, inexpensive, and simple modality is felt to be an attractive alternative in early detection of this abnormality. The ECG parameters on CSFP discussed in this study include; p-wave dispersion, QT interval dispersion, QRS intrinsic (Tpeak-Tenddeflection duration), and QRS fragmentation. Further studies are needed on the ECG image in CSFP so that in the future ECG can be a cheaper and non-invasive diagnostic modality for CSFP compared to coronary angiography.

Safety of low-dose dobutamine stress test in coronary slow flow phenomenon

Purpose: To investigate the feasibility and safety of a low-dose dobutamine stress test in coronary slow flow phenomenon (CSFP) patients.Methods: One hundred and forty-two CSFP patients, and forty-four patients without CSFP or significant epicardial coronary stenosis who served as the control group, were retrospectively reviewed. All patients were infused intravenously with dobutamine at an initial infusion rate of 5 μg/kg/min which was then increased at 8-min intervals to 10, 15, and 20 μg/kg/min. Symptoms and echocardiography were monitored simultaneously.Results: Patient tolerance decreased as the doses of dobutamine increased. No termination of the test occurred without dobutamine or at the infusion rate of 5 μg/kg/min. Nonetheless, when the infusion rates were adjusted to 15 and 20 μg/kg/min, the incident of side effects reached up to 30.9 %, and a few patients experienced ST-segment depression in precordial electrocardiographic leads. There were no induced arrhythmias without dobutamine, while the incidence of arrhythmias was highest at the infusion rate of 20 μg/kg/min. Malignant arrhythmias such as ventricular fibrillation and sustained ventricular tachycardia, were not detected. No significant differences were showed in echocardiogram result for left ventricular ejection fraction (LVEF) between CSFP and control group (63.7±7.9 in the CSFP group, versus 64.3±7.2 in the control group; p = 0.63).Conclusion: A low-dose dobutamine stress test is safe and feasible in CSFP patients.

Association between atrial fibrillation and coronary slow flow

Background The relationship between arrhythmia and coronary slow flow (CSF) is unclear. We aimed to explore the association between atrial fibrillation (AF) and CSF. Method In this cross-sectional study, we included 2,060 participants patients from PCI-registry (NCT 02498470) who underwent coronary angiography with clinical chest pain and without significant coronary stenosis. According to coronary blood flow rate measured by the thrombolysis in myocardial infarction frame count (TFC) method, CSF was defined as TFC>27. AF was identified by ECG performed during hospitalization. We used logistic regression to assess the association between AF and CSF. Results Among 2,060 participants, 132 participants were diagnosed with AF. CSF rates were higher in AF group than in the control group (22.0% vs 13.9%, P=0.011). Logistic regression showed that AF was independently associated with CSF after adjustment for traditional risk factors (OR=2.06; 95%, 1.28–3.34; P=0.003). Conclusion Our study demonstrated that AF was association with increased risk of CSF. Further studies are needed to confirm this finding and explore the potential mechanism. FUNDunding Acknowledgement Type of funding sources: None.

CORONARY SLOW-FLOW PHENOMENA AND ARRHYTHMIAS

A 50 years old smoker male with arrhythmias and non-obstructive coronaries diagnosed as a case of coronary slow flow phenomenon.

Plasma Atherogenic Indexes Are Independent Predictors of Slow Coronary Flow

Background Although the pathophysiology of coronary slow flow (CSF) has not been fully elucidated, emerging data increasingly support potential role for subclinical diffuse atherosclerosis in the etiology of CSF. We aimed to investigate relationship between atherogenic indices and CSF. Methods 130 patients with CSF diagnosed according to Thrombolysis in Myocardial Infarction (TIMI)-frame count (TFC) method and 130 controls who had normal coronary flow (NCF) were included in this retrospective study. Atherogenic indices (atherogenic index of plasma [AIP], Castelli risk indices I and II [CRI-I and II]) were calculated using conventional lipid parameters Results The logistic regression analyses demonstrated that AIP (OR, 5.463; 95% confidence interval [CI], 1.357–21.991; p = 0.017) and CRI-II (OR, 1.624; 95% CI, 1.138–2.319; p = 0.008) were independent predictors of CSF. Receiver operating characteristic analysis showed that the optimal cutoff value to predict the occurrence of CSF was 0.66 for AIP (sensitivity, 59%; specificity, 73%; area under curve [AUC], 0.695; p < 0.001) and 3.27 for CRI-II (sensitivity, 60%; specificity, 79%; AUC, 0.726; p < 0.001). Conclusions AIP and CRI-II levels were independent predictors of CSF, suggesting that atherogenic dyslipidemia may contribute to the pathophysiology of CSF.