User:Tombuckley23/sandbox

Physiology Article Evaluation
This article contains well cited information from multiple sources with a couple of stated points that are not supported by evidence from a citation in the "Women in Physiology" and "Human Physiology" sections. All of the information inside the article was relevant to the topic of physiology and was not distracting from the main points of the article. The article does appear extremely neutral to me and lacks any real biases that are glaringly noticeable. The information was from multiple different sources like books and other encyclopedias along with information from websites like ship.edu. All of the sources seem to be informational and lacking in bias or strong opinions due to their intent to inform or teach objective facts about physiology. The few links that I checked all led me to the proper article or title that was cited. The article appears to be free from plagiarism and does a good job of paraphrasing so as to introduce the information in a different way than the original source. The article has relevant historical information but lacks recent developments after the 1950s in the field of physiology. Including some of the more major advancements in recent years could bring the article more up to date. This article very much so aligns with the ways we've discussed physiology in class.

Premature Ventricular Contraction
This is the article I have chosen to make changes to. Some of these changes will be finding citations for certain statements that lack them or the eradication of these statements. I also intend to add details that may not be present in the sections that already exist. This is a pretty intensive article already but I will find information that is missing and ensure that the information included in the article is accurate. I will add more to the prevalence heading and add better descriptions of the signs/symptoms, treatments and causes headings as well.

Some sources I can use to help make this article better are:

http://www.mayoclinic.org/diseases-conditions/premature-ventricular-contractions/basics/definition/con-20030205

http://emedicine.medscape.com/article/761148-overview#a7

http://www.medicinenet.com/premature_ventricular_contractions/page1.htm

http://www.merckmanuals.com/home/heart-and-blood-vessel-disorders/abnormal-heart-rhythms/ventricular-premature-beats

https://www.ncbi.nlm.nih.gov/pubmed/11868062

http://circep.ahajournals.org/content/5/1/229

http://www.heartrhythmjournal.com/article/S1547-5271(16)30503-3/abstract

https://www.verywell.com/premature-ventricular-complexes-pvcs-1745222

https://www.aarpmedicareplans.com/channel/premature-ventricular-complexes-pvc_riskfactors

Prevalence
Single PVC are common in healthy persons. The prevalence of PVCs has been estimated to be about 1% to 4% for the general population. Age has been seen to play a major role in the occurrence of PVCs throughout the population. The prevalence is seen to be under 1% for those under the age of 11 and ranges all the way up to 69% in subjects that are older than 75 years. Older patients are more likely to experience PVCs and this may be due to its prevalence in patients with high blood pressure and heart disease, which are both commonly seen more in patients of older ages. In 101 people free of heart disease during 24 hours Holter monitoring, 39 had at least 1 PVC, and 4 at least 100. Heart disease was excluded after physical examination, chest x-ray, ECG, echocardiography, maximal exercise stress test, right- and left-heart catheterization and coronary angiography. In 122,043 United States Air Force flyers and cadet applicants during approximately 48 seconds of ECG 0.78% (952 males) had PVC within all age groups, but with increased incidence with increasing age. A study published in 2002 shows that based on only a 2-minute ECG, which is a relatively short measuring period for the detection of PVCs, these contractions are present in >6% of middle-aged adults and that independent of other factors, hypertension is associated with a 23% increase in the prevalence of PVCs.

Signs and symptoms
Although there are many signs and symptoms associated with PVCs, PVCs may have no symptoms at all. An isolated PVC is hard to catch without the use of a Holter monitor. PVCs may be perceived as a skipped heart beat, a strong beat, or a feeling of suction in the chest. They may also cause chest pain, a faint feeling, fatigue, or hyperventilation after exercise. Several PVCs in a row becomes a form of ventricular tachycardia (VT), which is a potentially fatal abnormal heart rhythm. Overall it has been seen that the symptom felt most by patients experiencing a PVC is the mere perception of a skipped heartbeat. The more frequently these contractions occur, the more likely there are to be symptoms, despite the fact that these beats have little effect of the pumping action of the heart and therefore cause minimal if any symptoms.

Some other possible signs and symptoms of PVCs:
 * Abnormal ECG
 * Irregular heart beat
 * Dyspnea
 * Dizziness
 * Feeling your heart beat (palpitations)
 * Feeling of occasional, forceful beats
 * Increased awareness of your heart beat
 * Perception of a skipped heartbeat

Causes
Premature ventricular contractions can occur in a healthy person of any age, but are more prevalent in the elderly and in men. They frequently occur spontaneously with no known cause. Heart rate turbulence (HRT) is a phenomenon representing the return to equilibrium of the heart rate after a PVC. HRT parameters correlate significantly with mortality after myocardial infarction (heart attack). One of the major causes of premature ventricular contractions is hypertension, which according to a 2002 study leads to a 23% increase in prevalence of PVCs. Some possible causes of PVCs include: * These two conditions can occur in patients that are taking diuretics such as water pills
 * Adrenaline excess;
 * High blood calcium;
 * Cardiomyopathy, hypertrophic or dilated;
 * Certain medicines such as digoxin, which increases heart contraction or tricyclic antidepressants
 * Chemical (electrolyte) problems in the blood;
 * Contact with Carina (trachea/bronchi) when performing medical suctioning stimulates vagus nerve
 * Drugs such as:
 * Alcohol;
 * Caffeine;
 * Cocaine
 * Theobromine;
 * Myocardial infarction;
 * Hypercapnia (CO2 poisoning);
 * Hypertension
 * Hypokalemia- low blood levels of potassium*
 * Hypomagnesaemia- low blood levels of magnesium*
 * Hypoxia;
 * Ischemia;
 * Lack of sleep/exhaustion;
 * Magnesium and potassium deficiency;
 * Mitral valve prolapse;
 * Myocardial contusion;
 * Myocarditis;
 * Sarcoidosis;
 * Smoking;
 * Stress;
 * Thyroid problems;

Risk Factors for PVC
The following stimulants, conditions and triggers may increase your risk of premature ventricular contractions:
 * Caffeine, tobacco and alcohol
 * High blood pressure (hypertension)
 * Anxiety
 * Underlying heart disease, including congenital heart disease, coronary artery disease, heart attack, heart failure and a weakened heart muscle (cardiomyopathy)
 * African American ethnicity
 * Male sex
 * Lower serum magnesium or potassium levels
 * Faster sinus rates