The left internal thoracic artery is now accepted as the conduit of choice for surgical revascularisation of the left anterior descending coronary artery and, with some reservations, other accessible coronary vessels. 1-3 We have previously described the use of transcutaneous duplex ultrasound in imaging the proximal part of the grafted internal thoracic artery and have related the estimated graft bloodflow to "runoff' in the graft territory.4-5 Several other groups have reported similar or complementary techniques and results.6-8 We report here the range of ultrasound findings in a prospective series of consecutive patients undergoing left internal thoracic artery grafting, and attempt to correlate ultrasound and angiographic findings in patients with suspected recurrent ischaemia after grafting. Our objectives were to define the range of "normality" of ultrasound graft measurements and to identify possible patterns which correlate with graft malfunction.Patients and methods Eighty three consecutive patients operated on by a single surgeon (TJS) were identified from operating lists and invited to attend for outpatient ultrasound assessment. They were interviewed by a doctor to ensure they were free from anginal symptoms. Patients rested supine for at least 20 minutes before examination. Examinations were performed at least two hours after any meal. Patients continued to take their usual drugs on the day of the study. Sixteen patients with 18 internal thoracic artery grafts presenting to our service over the same period with suspected recurrent ischaemia after previous internal thoracic artery grafting underwent a duplex ultrasound examination followed by angiography. Coronary and graft angiography were performed by standard techniques from a femoral approach using 7FG catheters.The technique of duplex ultrasound assessment was as previously described.4-5 A Diasonics (Bedford, United Kingdom) ultrasound system (Diasonics Spectra) was used with a 5 MHz linear array probe and colourflow Doppler facility. The upper left parasternal and supraclavicular transducer positions were used. The colourflow facility was used to identify the origin of the internal thoracic artery as it arose from the first part of the subclavian artery. The diameter of the vessel was measured with the transducer as near to 476 on 7 June 2019 by guest. Protected by copyright.

An rSr' pattern with QRS duration of less than 0.12 s in the right precordial leads can be due to incomplete right bundle branch block (which may progress to complete right bundle branch block) or can be a normal electrophysiological variant. To identify other ECG features that may help to distinguish between these two possibilities, ECGs of 15 patients who progressed from normal to complete right bundle branch block through an intermediate rSr' pattern of incomplete right bundle branch block were analysed. The following features in the right precordial leads (V1, V2) that preceded or accompanied the appearance of the rSr' were identified: diminution of the S wave depth (100%), inversion of ratio of the S wave depth to SV1 > SV2 (93%), slurring of the downstroke or upstroke of the S wave (27%) and prolongation of the QRS duration to > or = 0.10 s (73%). When a further 79 subjects with rSr' pattern in the right precordial leads and QRS duration of < 0.12 s were divided into those with SV1/SV2 ratio > 1.0 and those with SV1/SV2 < 1.0, compared with the latter the subjects with SV1/SV2 ratio > 1.0 were found to be significantly older (59.8 +/- 18.4 years vs 32.8 +/- 18.1 years, P < 0.001), to exclusively show S wave slurring (37% vs 0%), and to more likely have a QRS duration > or = 0.10 s (74% vs 7%).(ABSTRACT TRUNCATED AT 250 WORDS)

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1. The aim of the present study was to investigate the effects of exercise and of sublingual glyceryl trinitrate on the pattern of blood flow, as studied by Doppler ultrasound, in internal mammary artery grafts performed to relieve severe stenosis of the left anterior descending coronary artery. The accessibility of the graft to transcutaneous ultrasound examination allows the effects of exercise and nitrate administration on coronary blood flow to be studied non-invasively. 2. Angina-free patients with left internal mammary to left anterior descending coronary artery grafts were studied using transcutaneous duplex ultrasound at rest, after leg exercise and after sublingual administration of 0.5 mg or 1 mg of glyceryl trinitrate. 3. Resting graft blood flow showed a biphasic pattern, with forward flow in both systole and diastole. Exercise caused an increase in time-averaged velocity of graft blood flow from 17.3 (3.3) to 24.0 (7.2) cm/s (P = 0.001), and of calculated volume flow from 44.7 (3.08) to 59.8 (5.89) ml/min (P = 0.002). Diastolic peak velocity increased from 36.1 (9.9) cm/s to 46.8 (16.2) cm/s (P = 0.04), while peak systolic velocity was unchanged. Nitrate administration caused a fall in systolic and diastolic blood pressure and an increase in heart rate; graft flow was maintained [time-averaged velocity 18.3 (6.2) cm/s before and 16.7 (5.7) cm/s after 500 micrograms of glyceryl trinitrate], but systole was shortened and the proportion of blood flow in diastole increased [systolic/diastolic flow ratio 0.558 (0.139) before and 0.374 (0.156) after 500 micrograms of glyceryl trinitrate, P = 0.01].(ABSTRACT TRUNCATED AT 250 WORDS)