The Endothelial Phlexus

6. What happens to Caleb’s systemic cardiac output as a result of his ventricular septal defect (VSD)? Explain your answer. Caleb’s systemic cardiac output will be decreased. His blood will enter the right ventricle be pumped to the lungs, return to the left ventricle and then be shunted back to the right ventricle. This causes more blood to enter the right ventricle. The extra blood then leaving the right ventricle causes a volume overload to the lungs. Because blood is being shunted back to the right ventricle, there is a lesser volume of oxygenated blood that leaves the heart to supply the rest of the body.

3. Describe the blood flow of the heart and the correct locations the blood enters and exits.

-Stage 2-Invlovment of chest area place places, mediastinum {structure at the middle of the heart}, pericardium or contralateral {opposite side} pleura

With auscultation, a systolic ejection murmur may be heard and described as soft and scratchy along the left upper sternal border (Renuka & Thenmozhi, 2015). Another physical finding is a wide fixed split of S2 which may or may not be present (Renuka & Thenmozhi, 2015). Diagnostic studies like an electrocardiogram may show rhythms including sinus, atrial fibrillation or atrial flutter (Renuka & Thenmozhi, 2015). Other diagnostic findings include cardiomegaly on a chest x-ray (Renuka & Thenmozhi, 2015). Children with VSD often present as underdeveloped and small for their age secondary to the increased need for caloric intake because of an increased work of breathing with decreased lung compliance (Spicer et al., 2014). With large defects, children present with harsh pansystolic murmur heard best at the left lower sternal border which may include a thrill (Goolsby & Grubbs, 2014). Also, electrocardiogram and chest x-ray findings are often consistent with left ventricular hypertrophy and cardiomegaly (Goolsby & Grubbs, 2014).

To avoid those long-term affects the patients should get an Atrial Septal Defect treated. To determine the plan for treatment the doctors look at the size of the hole. The affected person has to have wall for the device to attach to get the cardiac catheterizations. If the patient has little to no wall present then open-heart surgery is used to fix it (Dr. Martin personal communication May 11th,

Malpositioned simply means that the aorta opens inside the heart in the wrong place. In a normal, healthy heart, the aorta is connected to the left ventricle, allowing oxygen rich blood to be pumped throughout the body. In patients suffering from tetralogy of Fallot, the aorta is slightly shifted to the right. This slight shift places the artery directly over the ventricular septum defect, which is typically located at the tip of the ventricles. As previously stated, the VSD allows oxygen rich and oxygen poor blood to mix together. With the aorta being directly over the VSD, this allows the mixture of blood to be pumped through the rest of the body, again contributing to the cyanotic presentation of the

7 Calcific aortic valve stenosis is the most common valvular pathology requiring valve replacement and showing some evidence of aortic valve thickening known as valvular sclerosis.

An atrial septal defect (ASD) is a hole in the heart. This hole is located in the thin tissue (septum) that separates the two upper chambers of the heart, the right and left atrium. This hole is present at birth (congenital). A few minutes after birth, this hole normally closes so that blood is not able to go between the right and left atrium.

Formation of the inter-atrial septum divides the primitive atrium into the right and left atrium. As discussed in (Jacobs C.J, 2006, pp. 89-100), the septum starts to form with the growth of the septum primum from the roof towards the endocardial cushions. The opening that forms between the septum primum and endocardial cushions is the ostium primum, this primum eventually fuses with the endocardial cushions and closes. Before the ostium primum closes cell death occurs at the upper portions of the septum primum and results in the ostium secundum. Simultaneously another septum forms, septum secundum on the right of the septum primum. Septum secundum grows until it overlaps the ostium

There are two common types of ectopic heartbeats, PVC -Premature ventricular contractions and PAC -Premature atrial contractions. First one, PVC can be found in both healthy and diseased hearts. “PVC is a premature beat (in the ventricle) that occurs earlier than the next expected beat. The normal (sometimes the P wave is not the same shape as other P waves) and these can be hard to pick out of a normal ECG. The identifying feature: The R-R interval between the PAC and the preceding beat is shorter than any of the other R-R intervals”

The heart has distinguished components that allow the pathway of electrical conduction to travel through the heart in order to effectively pump blood through the body. The electrical impulse initiates in the Sinoatrial node (SA node), which is located in the posterior wall of the right atrium, near the superior vena cava. It is also known as being the physiologic pacemaker of the heart and has an intrinsic firing rate of 60-100 impulses/min. From the SA node, the electrical impulse flows directly to the Atrioventricular node (AV node) with the guidance of intercalated discs and gap junctions. The AV node is located in the back section of the interatrial septum near the coronary sinus and tricuspid valve. Here, there is a delay of .1 seconds to allow the atria to contract and the ventricles to fill. In addition, this delay regulates the ventricles if there were an abnormal atrial rhythm. The AV node works as a secondary pacemaker if the SA is irregular, firing at 40-60 pulses/min. After leaving the AV node, the electrical impulse travels to the bundle of His. The bundle of His forms the only myocardial connection between the atria and ventricles. Additionally, the bundle of His divides the bundle branches into left and right and innervates the ventricles through Purkinje fibers.

Dysrhythmia, also known as arrhythmia, is a change in the regular rhythm of the heartbeat. At times the heart may seem to beat rapidly, very slowly, irregularly, or even skip a beat. Some of these changes are

When a ventricular septum defect occurs, a mixing of oxygen rich and oxygen poor blood takes place. A ventricular septum defect is a hole in the septum, or the wall between the left and right chambers of the heart. This hole happens to be in between the lower two chambers, or ventricles. The left ventricle receives oxygen rich blood from the lungs, while the right ventricle houses the oxygen poor blood from the body. The purpose of the separation by the septum is to prevent a mixture of the blood. Therefore, as long as there is a defect preventing the separation, the heart will continue to pump a mixture of the blood to the rest of the body. This causes the cells of the body to not receive all of the required oxygen that it would normally obtain with a fully intact septum, thus causing the cyanotic, or blue, appearance of the patient.

There is a such thing as a heart valve disease. All four valves can be stenotic (hardened, restricting blood flow); the conditions are called tricuspid stenosis, pulmonic stenosis, mitral stenosis or aortic stenosis. Valvular insufficiency. Also called regurgitation, incompetence or "leaky valve", this occurs when a valve does not close tightly. A heart valve is a heart valve normally allows blood to flow in only one direction through the heart. The four valves commonly represented in a mammalian heart determine the pathway of blood flow through the heart. A heart valve opens or closes incumbent on differential blood pressure on each side. A heart valve is the aortic valve and the mitral valve are the most commonly replaced valves. Pulmonary

The heart is a muscular pump about the size of a fist. This muscle is continuously pumping blood to the circulatory system at a rate on average of 100,000 times a day. Arrhythmia’s can cause an abnormal rhythm to this rate because of a change in the heart’s electrical system. These arrhythmias can either cause the heart to beat too slowly, bradycardia, or tachycardia, where the heart beats too fast. Supraventricular Tachycardia (SVT) is one specific form of tachycardia. When a person develops SVT it causes the heart tissue to develop activity similar to a pacemaker in the upper chambers, or the region above the ventricles (AHA, 2015). This produces an abnormally fast heartbeat. Understanding this condition is