The Effect of Slow Coronary Artery Flow on Microvolt T-Wave Alternans.
BACKGROUND
Slow coronary artery flow (SCF) is characterized by angiographically confirmed delayed vessel opacification in the absence of any evidence of obstructive epicardial coronary artery disease. Microvolt T-wave alternans (MTWA) is defined as beat-to-beat changes in shape, amplitude, or timing of ST segments and T waves, and is utilized in predicting sudden cardiac death and life-threatening malign ventricular arrhythmias in high-risk patients. In our study, we aimed to evaluate the effects of slow coronary artery flow on MTWA.


METHODS
Thirty-nine consecutive patients (SCF group: 6 women and 33 men; mean age, 49 ± 10 years) with angiographally documented SCF in at least 1 major epicardial artery and 39 patients (control group: 13 women and 26 men; mean age, 50 ± 10 years) with normal coronary arteries were included in the study. Coronary flow rates of all patients were calculated by thrombolysis in myocardial infarction frame count (TFC). The MTWAs of all patients were analyzed using the time-domain modified moving average method by means of a treadmill exercise stress test.


RESULTS
The age distribution , body mass index, and diastolic and systolic blood pressure (BP) were similar in the SCF and control group. In the SCF group, the three epicardial coronary artery corrected TFCs and mean TFCs were significantly higher than in the control group (for all, p < 0.001). MTWA positivity in the SCF group was statistically significant compared to the control group (p = 0.006). Spearman's correlation analysis, showed a positive correlation between MTWA and right coronary artery (RCA) TFC and mean TFC (r = 0.368, p = 0.001 and r = 0.271, p = 0.016, respectively). In linear regression analysis, only the right coronary artery TFC was correlated with positive MTWA (p = 0.001).


CONCLUSIONS
The results of our study suggest that diagnosed SCF is associated with MTWA positivity. Furthermore, we determined that only RCA TFC was predictive of positive MTWA.


BACKGROUND
Microvolt T-wave alternans; Slow coronary flow.
Mehmet Akif Ersoy Thoracic, Cardiovascular Surgery Training and Research Hospital, Cardiology Department, Istanbul, Turkey.
Ozgur
O
Surgit
Mehmet Akif Ersoy Thoracic, Cardiovascular Surgery Training and Research Hospital, Cardiology Department, Istanbul, Turkey.
Mehmet
M
Erturk
Mehmet Akif Ersoy Thoracic, Cardiovascular Surgery Training and Research Hospital, Cardiology Department, Istanbul, Turkey.
Ozgur
O
Akgul
Mehmet Akif Ersoy Thoracic, Cardiovascular Surgery Training and Research Hospital, Cardiology Department, Istanbul, Turkey.
Mehmet
M
Gul
Mehmet Akif Ersoy Thoracic, Cardiovascular Surgery Training and Research Hospital, Cardiology Department, Istanbul, Turkey.
Hamdi
H
Pusuroglu
Mehmet Akif Ersoy Thoracic, Cardiovascular Surgery Training and Research Hospital, Cardiology Department, Istanbul, Turkey.
Ibrahim Faruk
IF
Akturk
Mehmet Akif Ersoy Thoracic, Cardiovascular Surgery Training and Research Hospital, Cardiology Department, Istanbul, Turkey.
Fatih
F
Uzun
Mehmet Akif Ersoy Thoracic, Cardiovascular Surgery Training and Research Hospital, Cardiology Department, Istanbul, Turkey.
Umut
U
Somuncu
Mehmet Akif Ersoy Thoracic, Cardiovascular Surgery Training and Research Hospital, Cardiology Department, Istanbul, Turkey.
Ahmet
A
Ayaz
Mehmet Akif Ersoy Thoracic, Cardiovascular Surgery Training and Research Hospital, Cardiology Department, Istanbul, Turkey.
Abdurrahman
A
Eksik