Sinus node artery

AO Aorta MPA Main pulmonary artery RSCV Right superior vena cava TV Tricuspid valve MV Mitral valve PV Pulmonary valve AV Aortic valve RA Right atrium LAA Left atrial appendage RV Right ventricle LV Left ventricle LV-PM Left ventricle, muscle IVS Interventricular septum CR Crista supraventricularis SN sinus node AVN + B Atrioventricular node LBB Left bundle branch. 

The adverse effects associated with the use of verapamil include constipation, sinus node blockade, prolongation of the PR interval, AV dissociation, hypotension, and pulmonary congestion." The risks may outweigh the benefits in patients with (1) a markedly elevated pulmonary capillary wedge pressure or pulmonary artery occlusion pressure, (2) a history of paroxysmal nocturnal dyspnea or orthopnea, (3) sick sinus syndrome or significant AV nodal disease in the absence of a permanent pacemaker, (4) low systolic blood pressure, and (5) a substantial outflow gradient.Verapamil should be avoided inpatients with heart failure owing to systolic dysfunction. There is no evidence that either /3-blockade or verapamil protects the patient from sudden cardiac death. 

Intrinsic sinus node disease has been associated with a number of pathologic processes. For example, coronary artery disease is frequently associated with sinus node dysfunction, although a direct causal link has not been established. 

Shaw DB. Chronic sinus node disease and coronary artery disease. Lancet. 1988 1 1277. 

Kyriakidis MK, Kouroukhs CB, Papaioannon JT, Christakos SG, Spanos GP, Avgoustakis DG. Sinus node coronary arteries studied with angiography. Am J Cardiol 1983 51 749-750. 

We now turn to an anatomical description of lymph nodes. The lymph node is surrounded by a thick, fibrous capsule and is subdivided into compartments by trabeculae. Inside the capsule is the subcapsular or marginal sinus, which forms the entry point of lymphatic fluid into the node, via the afferent vessel. The lymph node cortex, which lies beneath the subcapsular sinus, is the location of the primary and secondary lymphoid follicles. The primary follicles are comprised of B-lymphocytes. An immune response stimulates B-cells to replicate and differentiate, converting the primary follicle into a secondary follicle or germinal center, surrounded by a zone of small lymphocytes. The paracortex surrounds the germinal centers and primary follicles and contains mostly T-lymphocytes. The medulla is composed of medullary cords, consisting of macrophages and plasma cells, and medullary sinuses. The medullary vessels include the arteries and veins, and the afferent and efferent lymphatic vessels, respectively, deliver the lymphatic fluid into and out of the lymph node. 

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