– including test injections – it is important to remember to check that the pressure tracing does not indicate wedging of the catheter tip against the vessel wall. If selective intubation via the femoral route proves elusive despite multiple attempts, the left radial route can offer a safer alternative A drawback of the left radial route is that right internal mammary artery (RIMA) grafts cannot be engaged, although successful intubation of the LIMA via the right radial route has been previously described [4]. A left radial approach is definitely helpful when the LIMA originates from the straight portion of the subclavian but selective cannulation may prove more difficult when it originates from the ascending limb where also catheters coming from the radial are challenged by the tortuosity of the subclavian (Figure 4.5). The first angiographic view for the LIMA requires panning from origin to the distal LAD. The views that best show the insertions are RAO cranial and left lateral. Collateral filling of other vessels should also be documented. Intubation to the diaphragm of a pedicle RIMA graft follows the same principles as for the LIMA, but with even greater care in view of the close proximity of the right internal carotid artery.
Coronary variants
Aberrant coronary anatomy is found in 0.16–1.3% of patients undergoing diagnostic angiography [5] and in 0.6% of subjects in autopsy series [6]. The anomalies can be of origination and course, of intrinsic coronary arterial anatomy (osteal stenoses, osteal aneurysm, myocardial bridging) or of termination (coronary fistula) [7]. Recent data suggest that close to 0.45% of the US population has anomalous origin of a coronary artery from the opposite sinus. [8] Some anomalies are easy to identify, such as abnormal origin of RCA (Figure 4.6) but others can be more subtle, such as anomalous non‐dominant circumflex (Figure 4.7). The culprit lesion can be missed if the aberrant anatomy is not identified (Figures 4.8 and 4.9). Systematic review to identify areas of the myocardium for which a vascular supply has not been demonstrated is helpful in this respect and also for identifying occlusions (Figure 4.9). Once it is known which vessel is anomalous, a review of the images can identify ghosting of the vessel. If there are no clues as to the origin, a systematic search starting with the most common variant is required. The diagnostic catheter shape needs to be changed as required to reach the wall of the aortic root in the area of interest. The most common coronary anomaly is an absent LMS. A slightly smaller curve catheter is required to intubate the LAD selectively (e.g. JL3.5 if JL4 preferentially and exclusively intubates the Cx). The Cx arising from the right coronary sinus can often be cannulated using the JR4 catheter, but a steep take off can require a multipurpose catheter whereas a posterior or high anterior origin can require an AR or AL shape. If the RCA arises from the left side separately from the LMS an AL1 or multipurpose catheter is most likely to be successful.
Figure 4.6 This 80‐year‐old obese female was admitted for angiography following a recent worsening of angina. She had a previous history of myocardial infarction. Preceding this presentation her angina symptoms had been stable for many years and were not previously investigated with angiography. A coronary ostium could not be engaged at the left aortic sinus. The left anterior descending (LAD), circumflex, and right coronary arteries originated from a single right‐sided ostium. The right coronary artery (RCA) (black arrows, a–d) was occluded distally. The left anterior descending (LAD) (white arrows, a–c) was critically stenosed proximal to a large diagonal and the circumflex (gray arrows, b–d) was critically stenosed in its mid course. The catheter partially obscures the LAD in (a) and the circumflex in (d).
Figure 4.7 These views were taken during primary angioplasty performed in a 41‐year‐old male who presented with an acute inferolateral myocardial infarction. No antegrade perfusion was evident in the circumflex territory (a to d), although retrograde collaterals to an obtuse marginal branch were seen in some views (green arrow, a). The right coronary artery (RCA) was occluded and filled retrogradely via the left anterior descending (LAD) (yellow arrow, a and b; d and e). The culprit lesion was in an aberrant circumflex arising from the right sinus (f). Following aspiration thrombectomy and stent deployment it was evident that the aberrant circumflex provided the principal collateral supply to a chronically occluded dominant RCA (yellow arrow, g).
Figure 4.8 Optimal angiographic views for specific segments in the circumflex and right coronary are indicated with a green tick mark. Some views that may be useful but are not generally recommended are indicated with an orange tick mark and inadequate views with a red cross.
Figure 4.9 This 47‐year‐old male with known coronary disease presented with deteriorating angina and reversible ischemia in the anterior territory on perfusion imaging. Conventional views (a–c) raised suspicion of a lesion in the left anterior descending (LAD) ostium due to haziness (a) but were limited by overlap at the ostium of the LAD due to unusual tortuosity (a). Unusual modification including a steep spider view and a lateral view with cranial angulation were required to delineate the lesion (d, e). The final angiographic result is shown after stenting (f).
Once the anomalous coronary vessel has been intubated the standard views are often sufficient for the mid and distal vessel if the heart has a normal position and orientation (Figures 4.2 and 4.3), while the views for the proximal vessel and ostium may need to be modified depending on the origin and course.
Ventriculography
Knowledge of ventricular function is essential to interpret the clinical relevance of coronary disease and planning appropriate treatment. Many patients have a contemporary assessment of left ventricular function by non‐invasive testing, which provides similar or superior definition of the left ventricular cavity volume and global and regional wall motion, with the advantage that most of them can also dynamically study wall thickness and tissue characteristics (echocardiography, magnetic resonance imaging, nuclear imaging) when attending for coronary angiography [1]. These modalities provide more information on the function and morphology of the left ventricle than conventional ventriculography and can obviate the need for further assessment. Ventriculography should be performed in the catheter laboratory if left ventricular function has not been assessed recently. The RAO view is standard, although an additional LAO view could be considered if assessment of the postero‐lateral wall, usually supplied by the circumflex, is likely to influence management.
