Post Surgery Atrial Fibrillation Monitoring Methods

Immediately following heart surgery, one of the common complications being monitored closely by health professionals is the incidence of atrial fibrillation (AF). It is said that there is a 20-40% reported incidence of atrial fibrillation, occurring 2-4 days after operation (Aerra 2006; Zaman, et. al.

2000; Aranki, et. al. 1996). Some studies show that the incidence can even be as high as 50% among the patients who have undergone heart surgery (Burke and Solomon 2003).It is estimated that one of every three people who have undergone heart surgery would suffer at least one episode of atrial fibrillation; and more than 40% of these people experience more than one episode (Matthew 2004).

It is said that majority of the first occurrence happen before the third day (Matthew 2004). It should be noted that 60% of those who experience more than one episode of experience the next episode immediately within two days (Matthew 2004; Funk et. al. 2003).Atrial fibrillation increases the risk for other complications such as heart failure, stroke, kidney damage and arrhythmias and among all the people who suffer from this condition, people who are over 65 years of age have the highest incidence (Giri, et. al.

2001; Matthew 2004; Walling 2001). While there are some who state that there is no significant change in the incidence of atrial fibrillation after surgery in the past two decades, that is, that there is a fairly constant incidence of atrial fibrillation, which is consistent in major areas around the globe (Matthew 2004), more reviews show that this is not so.Studies on the trends of the incidence of atrial fibrillation show that there is actually a significant increase in the rate of atrial fibrillation after surgery in the past 20 years. It is even predicted that by the year 2050, the numbers would reach more than 15 million people (“Secular trends in incidence of atrial fibrillation…” 2006). The most recent study shows that there is an increase in the incidence of post-op AF from 2.

2 million Americans in the late 90’s to 5. 1 million in 2006 (“Secular trends in incidence of atrial fibrillation…” 2006).A median incidence of 3. 5 million happened in 2001 in the US while Europe had an estimated 6 million (“Clinical trends in atrial fibrillation… 2001).

A study done by Ohsawa, et. al. (2005) in Japan also shows an increase in the incidence of atrial fibrillation after surgery from the 1980s, 1990s and up to 2005. This is consistent with the research data saying that there is an increasing incidence in AF after surger since the 1960s (“Secular trends in incidence of atrial fibrillation…” 2006). Comparison of the methods of monitoring atrial fibrillationThe continuously rising incidence of AF and the rising population of people above 65 years old could thus, realize the predicted incidence of AF in the 2050’s. It is only logical, then, to find ways for immediate diagnosis and monitoring of atrial fibrillation in order to contribute to the decline in its incidence and occurrence.

To reduce the incidence means immediate treatment (“Secular trends in incidence of atrial fibrillation…” 2006); and immediate treatment involved immediate diagnosis and proper monitoring.The methods of monitoring the incidence of atrial fibrillation have not changed much in the past two decades (Atrial Fibrillation Diagnosis n. d. ). Even in the 1980s, ECGs, particularly, resting ECGs, and recorders had already been used to determine the incidence of atrial fibrillation (Heeringa, et. al.

2006). However, continuous monitoring through holter and event monitors were not as widely used in the past (Funk, et. al. 2003). The monitoring methods that have always been used are the active and passive types of monitoring tests.The active tests involve deliberate inducement of irregular heartbeats.

Among these are electrophysiology (EP) testing or mapping, and the stress test. In the Electrophysiology testing and mapping, tubes with electrodes are inserted in the patient’s blood vessels in the heart in order to obtain a more accurate picture of the electrical impulses in the heart. Using this method, the heart is deliberately made to beat at a specific rate to trigger irregularity in heart beats (“Diagnosis of Atrial Fibrillation” 2007).Meanwhile, the stress test involves close monitoring (using an ECG) of the heart activity while the patient is made to exercise. It may or may not involve drugs for heart stimulation (“Diagnosis of Atrial Fibrillation” 2007).

Passive tests are used when the patient has to be monitored in regular daily conditions. Among these are the electrocardiogram (ECG), the holter monitoring, echocardiogram, event monitoring and blood tests (“Diagnosis of Atrial Fibrillation” 2007). Passive tests are the more common monitoring methods.In the Rotterdam Study, for example baseline and follow-up examinations were done using 10-s, 12-lead ECGs, and recorders.

Here, ECGs were used to diagnose the AF or atrial flutter (Heeringa, et. al. 2006). The determination of the occurrence of atrial fibrillation is usually done using an electrocardiogram (ECG) (Matthew 2004).

By using an electrocardiogram, the incidence of atrial fibrillation can be monitored whenever irregular heart beat is suspected (“Atrial Fibrillation” 2007).This method can determine the presence or absence of P waves which represents the waves of depolarization from the SA node to the atria by determining any unorganized electrical activity or by determining any irregularity in the R-R interval, caused by any irregularity in the impulses being sent to the ventricles (Klabunde 2007). In other words, an ECG is like an EP in that it measures the electrical impulses in the heart and its main purpose is to determine both the timing and duration of each electrical impulse (“Diagnosis of Atrial Fibrillation” 2007).The data from this monitoring method could then be used to provide an idea on the electrophysiological features and the possible reason for the event (Lip, Singh and Watson 1995).

It involves electrodes that are placed on the skin of the patient and is considered as one of the first steps in determining or documenting atrial fibrillation. ECG is used to monitor incidence of atrial fibrillation immediately after surgery and while the patient is still at the hospital.Since atrial fibrillation occurs 2 to 5 days after surgery, the patient must be monitored by ECG in the hospital for no less than 2 days post-op for a sign of the first episode. In previous studies, There is a mean 13 additional hours of stay in the ICU and 2 days in the ward for patients who have shown signs of AF(Funk et. al 2003, Matthew 1996). The importance of determining whether the atrial fibrillation is paroxysmal or chronic must be especially noted.

For the paroxysmal type, Holter monitoring must be done for the documentation (“Atrial Fibrillation” 2007; Lip, Singh and Watson 1995).Holter monitors are used for 24 hours to catch any episode of irregular heartbeat. It provides data about the heart rythms and can identify disturbances in the usual activities of the patient (“Diagnosis of Atrial Fibrillation” 2007). For intermittent palpitations, this method cannot be used (Lip, Singh and Watson 1995).

For patients with such palpitations, a transtelephonic event monitor is usually preferred, allowing the transmittal of electrocardiographic conditions using a telephone (Lip, Singh and Watson 1995) and thus a possible retrieval of the abnormal episodes.Such monitor is relatively cheaper compared to the others. The event monitor works in the same way except that it is used for a much longer period, about a month. Based on the results from these monitors, whether or not a case is atrial fibrillation can be checked by a medical professional (“Understanding Atrial Fibrillation” 2005). Unlike the other methods of monitoring atrial fibrillation, event recorders and hotlers are the only methods that allow monitoring outside the clinical setting.Because patients still develop atrial fibrillation after being monitored and discharged in the hospital, and can occur at any point during the recovery phase (Funk et.

al 2003), continuous monitoring must be done. Continuous electrocardiographic (ECG) monitoring through holter or event monitoring can be used from 24 hours (holter) to 240 hours (event) to allow this (Funk et. al. 2003). Sometimes, monitoring should be extended to even a month after discharge, at home, as atrial fibrillation can still develop at such point (Funk et. al 2003; Lahey et.

al 1998).Waves are used in the Echocardiogram or Doppler echocardiogram. Using these waves, detailed images of the patient’s heart size, structure and motion, blood volume, speed and direction of the blood volume are produced (“Diagnosis of Atrial Fibrillation” 2007). In addition, this method can also determine the functions of the ventricles and can sometimes establish proper functioning (Lip, Singh and Watson 1995).

Conclusion All the methods seem necessary in predicting and monitoring atrial fibrillation after surgery. After all, each method has a specific use for a specific case.However, among these methods, it is through holter and event recorders that the patient’s heart condition during normal activities could be monitored cost effectively. This is very important because the status of the patient should be determined most significantly under normal circumstances.

After all, a patient has a life to live and ideally, can only stay being monitored at clinic for a certain period—and monitoring, intervention and caring procedures should be tailored based on the patient’s conditions under these normal circumstances.Using these methods, the actual incidence of AF can be monitored from one day to two weeks after surgery which could ensure less errors and more efficient detection. Still, it is important to note that theoretically, among the methods, the p-wave duration in the signal-averaged ECG brings the most potential in predicting atrial fibrillation because of its high sensitivity and negative predictive value (Hakala and Hedman 2003).Its low positive predictive value, though, affects its usefulness (Hakala and Hedman 2003). The detailed analysis of ECG, as well as the measurement of heart rate variability do not provide much information on the risk of developing AF (Hakala and Hedman 2003).

Atrial pacing also shows much promise in a cost-effective diagnosis of the incidence of atrial fibrillation (Hakala and Hedman 2003).Referencehttp://en.wikipedia.org/w/index.php?title=Atrial_fibrillation&oldid=109578975