Explore how the heart's electrical system generates normal rhythm and what goes wrong in atrial fibrillation, atrial flutter, supraventricular tachycardia, and bradyarrhythmias. Learn the mechanisms behind each condition, how they are diagnosed, and why specific treatments like medications, ablation, and pacemakers are recommended.
If you have been told you have a heart arrhythmia — or someone close to you has — you have probably already experienced the strange combination of concern and confusion that tends to follow that conversation. The word "arrhythmia" sounds alarming, but it covers an enormous range of conditions, from brief blips that are barely noticeable to persistent rhythm disturbances that carry real risks. The problem is that without a clear understanding of what is actually happening in your heart, it is nearly impossible to evaluate what you are being told, ask the right questions, or feel confident in any decision you make about treatment.
This course exists to fix that. It is not a substitute for your cardiologist — nothing here should replace a real conversation with the physician who knows your specific situation. But it will give you a working mental model of how your heart's electrical system functions, what goes wrong in each of the major arrhythmia families, and why the treatments your doctor recommends are designed the way they are. By the end, you should be able to walk into a cardiology appointment as an informed participant, not a passive recipient of decisions made on your behalf.
Your heart is, at its core, a pump — but it is a pump driven by electricity. Every heartbeat begins as a tiny electrical signal generated in a specialized cluster of cells in the upper right portion of your heart. That signal travels along a precise pathway, triggering the muscle to contract in a carefully coordinated sequence: upper chambers first, then lower chambers, in a rhythm that repeats sixty to one hundred times per minute in a healthy adult at rest.
An arrhythmia (from the Greek a- meaning "without" and rhythmos meaning "rhythm") is any disturbance to this electrical sequence — whether in the rate of firing, the pathway the signal travels, or the coordination between chambers. Some arrhythmias make the heart beat too fast (tachyarrhythmias), some make it beat too slowly (bradyarrhythmias), and some disrupt the organized coordination between chambers without necessarily changing the overall rate in an obvious way. What all of them share is that the normal electrical choreography has been disrupted.
It is important to understand from the outset that arrhythmias are not rare. Atrial fibrillation alone affects tens of millions of people worldwide and becomes increasingly common with age. Many people live with arrhythmias for years before they are diagnosed. Many others are diagnosed incidentally — during a routine physical or while wearing a fitness tracker — and have never felt a symptom. This variability is one of the things that makes arrhythmias both interesting and important to understand clearly.
This course focuses on four major families of arrhythmia, chosen because they are among the most common, the most clinically significant, and the most frequently encountered by people seeking to understand their own diagnosis.
Atrial Fibrillation (AFib) is the most common sustained cardiac arrhythmia in adults. In AFib, the upper chambers of the heart (the atria) fire chaotically instead of contracting in an organized way. The result is an irregular, often rapid heartbeat — and, critically, a risk of blood clots forming in the heart and traveling to the brain. Understanding AFib means understanding not just how it feels but why stroke prevention is often the most urgent treatment priority, even when the rhythm itself feels manageable.
Atrial Flutter is a close relative of AFib that involves a rapid but organized circular electrical loop in the right atrium. Flutter and AFib frequently coexist in the same patient, and the distinction matters because their mechanisms and treatment responses differ in important ways.
Supraventricular Tachycardia (SVT) is a family of arrhythmias in which abnormal electrical pathways cause sudden bursts of very rapid heart rate — sometimes over 200 beats per minute — that start and stop abruptly. SVT is often frightening when it occurs, but in most cases it does not carry the stroke risk of AFib. Understanding its subtypes and triggers helps make sense of both the experience and the treatment options.
Bradyarrhythmias are arrhythmias characterized by an abnormally slow heart rate. This family includes sick sinus syndrome, in which the heart's natural pacemaker fails to fire reliably, and heart block, in which signals are delayed or blocked at the relay station between the upper and lower chambers. Bradyarrhythmias are the primary reason pacemakers are implanted.
The course is organized in a deliberate sequence, because each section builds on the one before it.
It begins with the anatomy and physiology of the normal heart — the four chambers, the valves, the electrical conduction system, and how a normal heartbeat is generated and maintained. This is not just background filler. You will return to this foundation constantly as you learn about each arrhythmia. Understanding what goes wrong requires a clear picture of what is supposed to go right.
From there, the course moves into diagnostic foundations: how arrhythmias are detected, what symptoms they produce, and what tools like the electrocardiogram (EKG), Holter monitor, and event monitor reveal — and what their limitations are. You will learn to interpret the basic language of a cardiac rhythm report well enough to understand what your own results are telling you.
The course then works through each arrhythmia family in depth, covering mechanism, symptoms, risk, and the full treatment landscape — including medications, cardioversion, catheter ablation, and pacemakers. For each treatment, you will understand not just what it does but why it is recommended, what the evidence says, and what the realistic tradeoffs are.
The course closes with cross-cutting concepts for navigating your own care: how to evaluate a treatment recommendation, what questions to ask before consenting to a procedure, and how to think about risk and quality of life when making medical decisions.
By the time you finish this course, you will be able to:
This course is designed to inform, not to reassure or alarm. Heart arrhythmias range from mildly inconvenient to genuinely dangerous, and it would not serve you to paper over that range with vague optimism. At the same time, an accurate understanding of your condition is almost always less frightening than an incomplete or distorted one — because it replaces uncertainty with something you can actually work with.
Every concept in this course is explained the way a cardiologist who loves teaching would explain it to a patient they respect: with precision, with honesty, and with the goal of leaving you better equipped to make decisions about your own health. That is the only kind of information worth your time.