1.True or False: Patent foramen ovale is an acyanotic heart defect.
True
Rationale: Patent foramen ovale is an example of an acyanotic heart defect which does not cause cyanosis in patients. Tetralogy of Fallot and tricuspid atresia are examples of cyanotic heart defects (McCance & Huether, 2019).
2. A patent foramen ovale can commonly cause all of the following except:
A. Heart Failure
B. Embolic Events
C. Atrial Dysrhythmias
D. Seizures
D. Seizures
Rationale: Right sided heart failure can be a late symptom of patent foramen ovale. Embolic events are possible due to the mixing of blood and transfer from right atrium to left or conversely left atrium to right. Finally abnormal conduction pathways may be present which could cause atrial dysrhythmias (McCance & Huether, 2019). Seizures are not commonly caused by a patent foramen ovale. Therefore the answer is D.
3. Transient ischemic attacks, related to a patent foramen ovale, cause what type of stroke?
A. Hemorrhagic
B. Embolic
C. Thrombotic
D. Lacunar
B. Embolic
An embolic stroke is a stroke caused by a thrombus that forms in a location outside of the brain. A hemorrhagic stroke is caused by a brain bleed. A thrombotic stroke is caused by thrombus formation in the cerebral arteries. Finally, a lacunar stroke is caused by foam cells and is usually associated with smoking. Therefore the answer is B. because the clot formed in the atria and traveled to the brain (McCance, Huether 2019).
4. The foramen ovale normally closes within what time frame?
A. One month
B. Six months
C. Two years
D. One Year
A. One month
Functional closure begins at birth with the change in pressure gradient associated with birth. Fibrin tissue develops to anatomically seal the flaps closed. This typically occurs within the first month of life (McCance, Huether 2019).
5. How could bearing down (Valsalva manuever) precipitate an embolic stroke?
A. Increased intrathoracic pressure increases atrial pressure and foramen ovale size
B. Heart rate increases while bearing down
C. Intrathoracic pressure decreases atrial pressure and lowers foramen ovale size
D. Gut Bacteria are disrupted by increased pressure in the abdomen
A.Increased intrathoracic pressure increases atrial pressure and foramen ovale size
Rationale: In the “Cryptogenic Stroke and High-Risk Patent Foramen Ovale: The DEFENSE-PFO Trial” (Lee et. al 2018) patients underwent TEE while instructed to bear down. The researchers were able to demonstrate that increased pressure increased R to L shunt and mobility of the foramen ovale into an open position. Therefore, while bearing down answer C. must be incorrect. Gut bacteria, answer D., do not seem to be affected by a valsalva maneuver . Finally heart rate usually decreases while bearing down in a valsalva maneuver so answer B. is also incorrect. All of these mechanisms will shift with the change of pressure in the thoracic cavity as the person ceases to bear down and heart rate and pressure normalizes. Therefore the combination of increased pressure while straining and the subsequent release of pressure after may have precipitated a stroke in this patient. The most correct answer is A.