Anatomy of the Ventricular Coronary Arteries in the Dog

Blair, Emil

doi:10.1161/01.res.9.2.333

Cited by 78 publications

(29 citation statements)

References 8 publications

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“…Worthy of further investigations are the changes induced by the altered performance of the ischemic right ventricle on the left ven tricular function when ischemia is not ex tended to the septum. In the present investi gation, performed in the anesthetized dog in which, unlike what is observed in humans, the right coronary artery does not supply the sep tum [9], we studied the effect of regional right ventricular ischemia on the activity of the right ventricle and the effect of pure (without involvement of the septum) general right ven tricular ischemia on the activity of the right and left ventricles. after the occlusion, the loop is shifted towards the right showing an increase in ventricular dimensions; a re duced difference between the diastolic and the systolic area is also evident.…”

Section: Discussionmentioning

confidence: 99%

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The Effect of Pure Right Ventricular Ischemia on Right and Left Ventricular Performance in the Anesthetized Dog

Gattullo

Casalucci²,

Gastaldi³

et al. 1993

Cardiology

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This study was planned to investigate the effect of ischemic dysfunction of the free wall of the right ventricle on right and left ventricular performance in the presence of a normally contracting interventricular septum. The experiments were performed in 6 anesthetized dogs in which echocardiogram, electrocardiogram, aortic blood pressure and left and right ventricular pressure were recorded. In the dog, the contractility of the septum is not affected by the occlusion of the right coronary artery which does not perfuse this part of the myocardium. Complete occlusion of the major individual ventricular branches and partial occlusion of the main right coronary artery did not impair right ventricular performance. Only complete occlusion of the main artery affected right and left ventricular function as revealed by echocardiogram. Reduced output by the ischemic right ventricle caused a reduction in left ventricular diastolic and systolic dimensions and in left ventricular developed pressure without any effect on left ventricular end-diastolic pressure.

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Section: Discussionmentioning

confidence: 99%

“…The dog was selected as an experimental model in which the left coronary artery is reported to supply at least one fourth of the margin of the right ventricle adjacent to the posterior longitudinal groove including the posterior part of the septum [9].…”

Section: Introductionmentioning

confidence: 99%

The Effect of Pure Right Ventricular Ischemia on Right and Left Ventricular Performance in the Anesthetized Dog

Gattullo

Casalucci²,

Gastaldi³

et al. 1993

Cardiology

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“…Numerous studies have detailed the distribution of canine circumflex artery blood flow; major ischemia in the LV lateral and posterior walls and the posterior papillary muscle are produced by proximal circumflex coronary artery occlusion. 34,35 ED is often defined at the peak of the electrocardiographic R wave. We used the time of maximum volume to define ED and the ED reference dimensions.…”

Section: Discussionmentioning

confidence: 99%

Dynamics of normal and ischemic canine papillary muscles.

Rayhill

Daughters

Castro

et al. 1994

Circulation Research

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This investigation was designed to elucidate the dynamics of the left ventricular (LV) papillary muscles. Miniature tantalum myocardial markers were placed on the tip and base of each papillary muscle in six dogs. Markers were also implanted into the LV myocardium to define two orthogonal equatorial diameters and the long-axis dimension. Two weeks later, after recovery from thoracotomy, markers were visualized by biplane fluoroscopy, and video images were recorded during control conditions, after autonomic blockade, after inotropic stimulation with calcium, after methoxamine infusion (to increase afterload), and after blood volume augmentation (to increase preload). Two days later, radiographic recordings were made before and after occlusion of the left circumflex coronary artery. Computer-aided analysis of the video recordings was used to determine three-dimensional coordinates of the markers. It was found that before circumflex coronary occlusion, the dynamraditionally, it has been held that the function of the left ventricular (LV) papillary muscles is to maintain the competency of the mitral valve during ejection, but a century ago Woods1 wrote:The musculi papillares are usually considered as having only to do with controlling the mitral and tricuspid valves. But they must also aid in expelling blood. For the exertion necessary to prevent the valves from flapping back into the auricles must also react on the ventricular wall and help it in its effort at contraction. They must then be looked upon as having the double function of controllers of the valves and true working muscles of the heart itself. The second goal of the present study was to test the hypothesis that the papillary muscles remain isometric during two critical periods within the cardiac cycle, isovolumic contraction (IVC) and isovolumic relaxation (IVR).We found that the papillary muscles shorten during ejection in a manner similar to the rest of the LV and their lengths change only very slightly during the isovolumic periods, except when affected by ischemia. Materials and Methods Surgical PreparationSix mongrel dogs of either sex (25 to 43 kg) were anesthetized with intravenous pentobarbital (25 mg/kg), intubated, by guest on May 11, 2018

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“…12 A number of studies have demonstrated the site of earliest activation of chronic human VT is normally in the subendocardium3-6 and that the majority of human VT is associated with infarcts extending into the interventricular septum.7-'6 Whereas the blood supply of the human interventricular septum arises from three to five large septal perforators that arise from the left anterior descending coronary artery, 75% of the canine interventricular septum receives its blood supply from a single artery, the anterior septal coronary artery. 17 To more closely mimic the anatomic substrate that gives rise to chronic VT in humans, we developed a canine model of chronic VT by creating ventricular septal Septal a.…”

mentioning

confidence: 99%

Anterior septal coronary artery infarction in the canine: a model of ventricular tachycardia with a subendocardial origin. Ablation and activation sequence mapping.

et al. 1994

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BACKGROUND In humans, chronic ventricular tachycardia (VT) is usually associated with myocardial infarcts that involve the interventricular septum. In an effort to more closely mimic the anatomic substrate that gives rise to chronic VT in humans, we developed a canine model of VT in which the anterior septal coronary artery was ligated. The site of earliest activation, the subsequent activation sequence, and the mechanism of VT associated with the resultant ventricular septal infarct was then evaluated to determine if this model accurately reflected the characteristics of human VT. METHODS AND RESULTS Seventeen dogs underwent occlusion-reperfusion ventricular septal infarcts. Four to 7 days later, electrophysiological studies were performed. VT was initiated by programmed electrical stimulation and terminated by pacing at a cycle length of 50% to 75% of the VT cycle length. Electrophysiological studies were performed using a 256-channel mapping system. A total of 15 VT morphologies were mapped in 9 animals. Fourteen of 15 morphologies had septal subendocardial sites of earliest activation and 1 had a septal midwall site of earliest activation. VT ablation was performed using a nitrous oxide cryoprobe and confirmed the site of earliest activation by subsequently rendering VT noninducible. Electrophysiological studies demonstrated four distinct VT activation sequences: (1) circular reentrant (n = 7), (2) concentric spread (n = 5), (3) figure-of-eight (n = 2), and (4) septal midwall (n = 1). CONCLUSIONS This canine model of ventricular septal infarction produces VTs with sites of earliest activation and activation sequences similar to those in humans. A reentrant mechanism as the basis of these arrhythmias is supported by the following observations: (1) all VT was initiated and terminated with programmed electrical stimulation; (2) VT activation sequences were consistent with reentry; and (3) precise interruption of the sequence terminated the VT and rendered it noninducible.

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Anatomy of the Ventricular Coronary Arteries in the Dog

Cited by 78 publications

References 8 publications

The Effect of Pure Right Ventricular Ischemia on Right and Left Ventricular Performance in the Anesthetized Dog

The Effect of Pure Right Ventricular Ischemia on Right and Left Ventricular Performance in the Anesthetized Dog

Dynamics of normal and ischemic canine papillary muscles.

Anterior septal coronary artery infarction in the canine: a model of ventricular tachycardia with a subendocardial origin. Ablation and activation sequence mapping.

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