The evaluation of myocardial blood flow with measurement technique to Fractional Flow Reserve in patients with myocardial bridging

AMAÇ: Fraksiyonel akım rezervi (Fractional Flow Reserve=FFR), koroner arter darlıklarında miyokardiyal iskeminin fonksiyonel olarak ciddiyetini belirlemede kullanılan bir indekstir. Bu çalışmada Miyokardiyal "bridge" (MB) olan olgularda miyokardiyal sistolik daralmanın sebep olabileceği iskeminin ciddiyetini belirlemede FFR indeksinin kullanılabilirliği araştırılmıştır. GEREÇ VE YÖNTEMLER: Çalışmaya sol ön inen koroner arterde (LAD) sistolik daralmanın $\geq$%70 olan 38 MB'li erkek hasta alındı. Tüm hastalara talyum 201 sintigrafi testi (TST) uygulandı. Miyokardiyal fraksiyonel akım rezervi basınç algılayıcı transdüseri olan bir intrakoroner klavuz tel ile ölçüldü. FFR 0.75 (negatif) idi. Alt gruplar arasında FFR indeksi açısından istatistiksel anlamlı fark saptanmadı (p>0.05). SONUÇ: Fraksiyonel akım rezervi, MB'nin miyokardiyal kan akımı üzerindeki etkisini incelemek için kullanışlı bir indeks değildir ve miyokardial "bridging" olgularında iskemiyi göstermede yetersiz kalmaktadır.AIM: Fractional flow reserve (FFR) is an index to determine the functional severity of myocardial ischemia in coronary stenosis. The aim of this study was to determine the usefulness of this index for establishing the severity of ischemia due to myocardial systolic narrowing in patients with myocardial bridging. MATERIAL AND METHODS: Thirty and eight male patients with myocardial bridging (MB) who had systolic narrowing $\geq$70% in the left anterior descending coronary artery (LAD) were enrolled in this study. Thallium 201 sintigraphy testing (TST) was performed in all patients. Myocardial fractional flow reserve was measured with an intracoronary guidewire-mounted pressure wire. A FFR value <0.75 was distinguished functionally significant stenosis (positive). According to the presence of perfusion disturbance in TST, the patients (mean age: 54±7 years) were divided into two groups (I: TST positive, II: TST negative) and sub-groups according to the value of FFR index (A: FFR positive, B: FFR negative). RESULTS: There was no significant difference between all groups related to the degree of mean systolic narrowing in LAD (p=0.6). The value of FFR has shown significant myocardial ischemia in 56% of patients in group I who had positive thallium testing. The FFR value was >0.75 (negative) in 67% of patients in group II who had negative TST. There was not found any statistical difference between FFR indexes in sub-groups (p>0.05). CONCLUSION: Fractional flow reserve is not a useful index to evaluate the influence of MB in myocardial blood flow and is insufficient to demonstrate ischemia in patients with myocardial bridging