A. Atrial Fibrillation(AFib or AF)

Atrial fibrillation is an irregular heartbeat that increases the risk of stroke and heart disease. Signs include dizziness, weakness, and fatigue. Treatment involves medication and lifestyle changes, and sometimes procedures such as cardioversion, ablation, pacemakers or surgery.1

Source: 1WebMD: http://www.webmd.com/heart-disease/atrial-fibrillation/

 

a. Causes and risk factors for atrial fibrillation

The conditions for inducing atrial fibrillation include:

  1. Existing heart diseases-One of the most important risk factors is existing heart disease, such as:
    • Heart valve disease
    • Heart failure
    • Coronary artery disease
    • Rheumatic heart disease
    • Cardiomyopathy
    • Congenital heart disease
    • Inflamed membrane or sac around the heart (Pericarditis)
  2. Age: If you are getting older especially after age 60, you are more likely to develop atrial fibrillation.
  3. Family: Some recent studies have shown a genetic component as atrial fibrillation often runs in families.2

Source: 2 http://www.stopafib.org/causes.cfm

 

b. Diagnosis of atrial fibrillation

Your doctor may execute several examinations to clarify your condition for diagnosing atrial fibrillation, the following:

  1. Electrocardiogram (ECG). The machine can record heart signal with electrodes attached to your chest, arms, and legs. Furthermore, ECG can observe heart rhythm, diagnose heart attacks, examine blood flow to and from the heart. This is a major examination to diagnose atrial fibrillation.
  2. Holter monitor. Atrial fibrillation occurs paroxysmally and ECG could not record it at the right time. Holter monitor is a portable machine to prolong recorded time for having more chance to diagnose atrial fibrillation. It continuously records your heart's electrical activity for at least 24 to 48 hours. Some newer models can record for up to 2 weeks.
  3. Event recorder. This portable machine is like Holter monitor. It allows a longer time to record heartbeats, typically 30 days at a time. You can choose to activate it for recording your heart beats when you have an atrial fibrillation attack.

 

c. Therapy options for atrial fibrillation

The atrial fibrillation treatment that is most appropriate for you will depend on how long you've had atrial fibrillation, how bothersome your symptoms are and the underlying cause of your atrial fibrillation. Generally, the treatment goals for atrial fibrillation are to:

  • Reset the rhythm or control the rate
  • Prevent blood clots

The strategy you and your doctor choose depends on many factors, including whether you have other problems with your heart and if you're able to take medications that can control your heart rhythm. In some cases, you may need a more invasive treatment, such as surgery or medical procedures using Catheters3.

Source: 3Mayo Foundation for Medical Education and Research (MFMER).

 

Individual AF treatment goals

AF treatment goals would be individualized, it is included the rate, rhythm convert(control) and stroke-prevention. However, AF patients still need a therapeutic strategy from a physician evaluation on their history, physical examination, blood test and other cardiac examination.

 

Prevention and Risk Reduction

Although no one is able to guarantee that a stroke or a clot can be prevented completely, there are some ways to reduce risks for these problems occurring.

After a patient has been diagnosed with atrial fibrillation, the ideal goals may include:

    • Stop AF and convert to normal heart beats (called Rhythm Control)
    • Lowering down heart rate to the tolerated heart rate (called Rate Control)
    • Preventing ischemic stroke (called prevention of Thromboembolism such as stroke)

 

Rhythm control

Rhythm control includes catheter ablation and medication maintenance.

Catheter ablation4: Sometimes medications or cardioversion to control atrial fibrillation doesn't work. In those cases, your doctor may recommend a procedure which was radiofrequency ablation to kill the area of heart tissue that's causing the erratic electrical signals and restore your heart to a normal rhythm.

On the other hand, doctors may be able to reset your heart to its regular rhythm (sinus rhythm) using a procedure called cardioversion to correct your condition, depending on the underlying cause of atrial fibrillation and how long you've had it.

Source: 4Mayo Foundation for Medical Education and Research (MFMER)

 

Rate control

Normal heart rate is 60-100 bpm. However, atrial fibrillation may reach more than 150 bpm. Heart rate control makes patient more comfort and less occurring of heart failure symptoms. The first choice of rate control is Beta-Blocker. Of course, you still need to be consulted by your cardiologist for using this medication.

 

d. Ischemic stroke prevention

A heart with atrial fibrillation induces thrombi from the left atrial appendage and the subsequent event is an ischemic stroke. Once atrial fibrillation is diagnosed, your physician will decide to prescribe anticoagulation medication like Warfarin or Edoxaban (one kind of new oral anticoagulation therapy, NOAC) to prevent a stroke. Sometimes a patient with atrial fibrillation has minimal symptoms or even no symptoms at all. Freescan device that can tell real-time rhythm is critical to stroke prevention of atrial fibrillation.


 

B. Arterial Stiffness

a. Causes and risk factors for arterial stiffness

Aging of arteries is associated with structural and functional changes of the vessel wall, which result in decreased vascular distensibility and elevated arterial stiffness. As a consequence of arterial stiffness, systolic blood pressure increases, causing a rise in left ventricular workload and subsequent hypertrophy, and diastolic blood pressure decreases, leading to an impaired coronary perfusion.5 

Source: 5Arterial Stiffness and Risk of Coronary Heart Disease and Stroke - The Rotterdam Study http://circ.ahajournals.org/content/113/5/657

 

b. Arterial age and arterial stiffness

Arterial age is an estimate of arterial stiffness. Your arteries age more slowly and more gracefully than the rest of you when nurtured with daily exercise, a healthful diet, and good relationships with family and friends. They age faster when they're constantly assaulted by cigarette smoke, foods laden with saturated and trans fats, chronic stress, and other traumas. Knowing your arterial age can give you a clearer picture of your heart's health. 6 

Source: 6How old are your arteries, Harvard Health Publications, January, 2010 

 

c. How to know the arterial age7?

Three currently available tools estimate artery "age" using pulse wave velocity and carotid intima-media thickness. 

1. Pulse wave velocity

Each heartbeat sends a wave of blood through the body's network of arteries. The stiffer the arteries, the faster this wave travels. Measuring the speed of the pulse wave provides information about how stiff or how flexible the arteries are.

2. Carotid intima-media thickness

The innermost layer of an artery's wall is called the intima; it provides a smooth surface for blood to flow through. The media is the middle layer; its muscle and elastic fibers let the vessel expand and contract with each heartbeat. The thicker the intima and the media, the more likely the artery is choked with cholesterol-filled atherosclerotic plaque.

3. Framingham score

The landmark Framingham Heart Study has been following the health of thousands of residents of one Massachusetts town since 1948. Data accumulated in the study have helped researchers create a general cardiovascular risk profile. With answers to a few questions, this tool estimates your chances of having a heart attack or stroke, needing bypass surgery or angioplasty, or developing peripheral vascular disease or heart failure. It also estimates your vascular age.

Source: 7How old are your arteries, Harvard Health Publications, January, 2010