Massage & Bodywork


Issue link:

Contents of this Issue


Page 41 of 106

C h e c k o u t A B M P 's P o c k e t P a t h o l o g y a t w w w. a b m p . c o m / a b m p - p o c k e t - p a t h o l o g y - a p p . 39 Watch "Heart Rate Variability" Sinus node Internodal pathways AV node AV bundle LeL bundle branch Right bundle branch Purkinje fibers The electrical conduction system of the heart. 1 The impulse travels to the atrioventricular node (AV node), located just above the ventricles. The AV node slows the impulse so the atria can complete their contraction before the ventricles begin. From the AV node, the impulse travels by way of the His-Purkinje network to the walls of the ventricles. The ventricles contract, pushing oxygenated blood to the rest of the body (left ventricle) and deoxygenated blood to the lungs (right ventricle). And then the cycle begins again with the next contraction of the atria. Arrhythmias are identified by problems in how an impulse is formed or in how an impulse is conducted through the heart. • Problems with formation: The SA node may initiate impulses too quickly or too slowly. Myocardial cells may also alter the speed of polarization and depolarization. In some cases, impulses can be generated spontaneously by cells outside the SA node, which causes disorganized and irregular contractions. • Problems with conduction: These problems center on the way impulses travel from the SA node to the AV node, and through the His-Purkinje network. Any disruption here is called a partial or complete heart block. TYPES OF ARRHYTHMIAS It's interesting to name the types of arrhythmias, and we will do so here mainly for the sake of vocabulary. However, this information is of low practical use when making decisions about massage therapy. In general, it may be helpful to remember that the most common forms of arrhythmia—atrial fibrillation and atrial fluttering—are generally manageable, but they can lead to serious complications if untreated. Ventricular arrhythmias are more likely to be medical emergencies. • Bradyarrhythmia: This is an abnormally slow heartbeat, typically under 50–60 beats per minute. • Premature or extra heartbeat: The signal to the heart is early, leading to a short pause and an extra-strong beat. This pattern can lead to other forms of arrhythmia. • Supraventricular arrhythmia: These problems start anywhere above the ventricle, and cause tachycardia, or a heart rate over 100 beats per minute. If this situation involves a conduction problem, the atria and ventricles may beat at different rates. Subtypes of supraventricular arrhythmia include: ° Atrial fibrillation: This is the most common form of arrhythmia, involving rapid but uncoordinated and weak contractions of the atria. This can be episodic or persistent. ° Atrial flutter: This situation causes the atria to beat 250–300 times per minute. It may be related to scar tissue from a myocardial infarction. ° Paroxysmal supraventricular tachycardia (PSVT): This causes a short episode of rapid heart rate involving both the atria and ventricles. It begins and ends very suddenly, often in the context of vigorous exercise. It is not usually dangerous. ° Ventricular arrhythmia: These versions of arrhythmia are much more dangerous than the other types. They start in the lower chambers of the heart. ° Ventricular tachycardia: This involves fast, organized contractions of the ventricles. When it only lasts for a few seconds it is not threatening, but it can persist for much longer, and it can lead to ventricular fibrillation. ° Ventricular fibrillation: This condition involves disorganized signals that cause the ventricles to quiver rather than pump. V-fib can lead to sudden cardiac arrest and death. SIGNS, SYMPTOMS, AND COMPLICATIONS Mild arrhythmias may be practically silent, creating no symptoms or just an occasional awareness of palpitations or a sense of pounding. Other symptoms include irregular heartbeat, dizziness, lightheadedness, shortness of breath, fatigue, faintness, and chest pain. Arrhythmias can be progressive, leading to more extreme symptoms and higher risks of related problems. Untreated frequent or persistent arrhythmias can cause serious complications. If the chambers of the heart don't empty fully, then blood inside can thicken into emboli. Then, when they are finally pushed out, they can go to the lungs, causing pulmonary embolism; or to the aorta where they might lodge in a coronary artery, causing a heart attack; or into the brain, causing a stroke. Untreated ventricular tachycardia can lead to ventricular fibrillation and a shutdown of the whole system in cardiac arrest.

Articles in this issue

Links on this page

Archives of this issue

view archives of Massage & Bodywork - NOVEMBER | DECEMBER 2020