Table of ContentsView AllTable of ContentsFactsWho is at Risk?Appearance on ECGTreatment and SurgeryManagement and PreventionOngoing Monitoring
Table of ContentsView All
View All
Table of Contents
Facts
Who is at Risk?
Appearance on ECG
Treatment and Surgery
Management and Prevention
Ongoing Monitoring
There are three degrees of heart block that are classified based on severity. With second-degree heart blocks, some signals from the atria (upper chambers of the heart) do not reach the vestibules (lower chambers).
There are two subtypes of second-degree heart block: Mobitz type 1 (also called a Wenckebach block), which may or may not cause symptoms, and Mobitz type 2, which can cause problems pumping blood and irregular heartbeats.
Fodor90
Quick 2nd-Degree Heart Block Facts
Heart blocksare disruptions in the electrical signals that regulate and coordinate movements of the heart muscle as it pumps blood. They range from first-degree (mild) to third-degree (severe). In severe cases, electrical signals from the atria never reach the vestibules.
Second-degree heart blocks partially disrupt the electrical signals. Healthcare providers categorize second-degree heart block subtypes—Mobitz type 1 and type 2—based on their physical signs on anelectrocardiogram(ECG), which records the electrical activity of the heart using electrodes on the chest. Here’s what providers look for:
Who Gets Diagnosed With 2nd-Degree Heart Block?
A wide range of conditions and medications can raise the risk of second-degree heart block. These include:
Symptoms
The symptoms of heart block depend on its severity. Whereas type 1 second-degree heart block doesn’t always cause symptoms, Mobitz type 2 is more likely to cause problems. Potential signs of second-degree heart block include:
Some people experience asymptomatic and temporary first-degree heart block. It can arise in otherwise healthy young adults when they’re sleeping or at rest.
A Good PrognosisIt can be concerning to learn you have second-degree heart block. Untreated, this condition can lead to severe and even fatal complications. But the outlook is positive. Mobitz type 1 heart block is often benign, and with monitoring and medical treatment, most people can manage a type 2 heart block.Although pacemakers can limit some activities, they improve quality of life; with second-degree heart block, you can resume most normal activities.
A Good Prognosis
It can be concerning to learn you have second-degree heart block. Untreated, this condition can lead to severe and even fatal complications. But the outlook is positive. Mobitz type 1 heart block is often benign, and with monitoring and medical treatment, most people can manage a type 2 heart block.Although pacemakers can limit some activities, they improve quality of life; with second-degree heart block, you can resume most normal activities.
It can be concerning to learn you have second-degree heart block. Untreated, this condition can lead to severe and even fatal complications. But the outlook is positive. Mobitz type 1 heart block is often benign, and with monitoring and medical treatment, most people can manage a type 2 heart block.
Although pacemakers can limit some activities, they improve quality of life; with second-degree heart block, you can resume most normal activities.
How 2nd-Degree Heart Block Type 1 Looks on ECG
Since second-degree heart block type 1 often doesn’t cause symptoms, healthcare providers usually only detect it on an ECG.
With Mobitz type 1 second-degree heart block, the PR intervals get longer, and QRS waves are delayed and then dropped, which happens cyclically and adopts a regular pattern. For instance, someone may have three P waves for every two QRS waves.
Treatment and Pacemaker Surgery
Acardiologist(heart specialist) will help you determine the best treatment for second-degree heart block. If you have no symptoms or are mild—as is often the case with type 1—you may not need apacemakerto regulate your heartbeat. Most people with Mobitz type 1 do not require a pacemaker. Instead, a cardiologist may recommend:
Implanting a pacemaker is an appropriate treatment for cases that will not resolve on their own and run the risk of complications like heart arrhythmia,cardiac arrest, and heart failure.
Management to Prevent 3rd-Degree Heart Block Progression
If you have second-degree heart block, your cardiologist or healthcare provider may recommend making lifestyle changes to prevent it from worsening.
Third-degree heart block is a medical emergency. It causes a complete disruption of electrical signals to the ventricles and can lead to severe complications.
Steps to promote heart health and prevent complications include:
If you have second-degree heart block, ongoing monitoring and follow-up are critical, even if you don’t have symptoms. Schedule regular follow-ups with a cardiologist. They will monitor your heart health and track any causes or complications of the condition.If you have a pacemaker, they will do regular maintenance checks.
In addition, your provider may recommendtracking your pulsedaily, showing you what to expect and what could mean trouble. Severe symptoms and signs of heart failure warrant calling your provider and getting emergency help. These include:
Summary
Second-degree heart block occurs when electrical signals from the upper part of the heart are disrupted on their way to the lower part. Healthcare providers break it down into two types: Mobitz type 1 (Wenckebach heart block) and Mobitz type 2. Adopting heart-healthy lifestyle changes and managing risk factors, like diabetes or high blood pressure, help prevent second-degree heart block from getting worse.
9 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.MedlinePlus.Heart block.American Heart Association.Heart conduction disorders.Karabag T, Kalayci B, Sayin MR, Erten T.Atrioventricular conduction defect associated with severe hyponatremia.Clujul Med. 2018;91(3):342-345. doi:10.15386/cjmed-846.Ata F, Khan HA, Choudry H, Khan AA, Tahir S, Cerqueira TL, Illigens B.A systematic review of the clinical characteristics and course of atrioventricular blocks in hyperthyroidism.Ann Med. 2024 Dec;56(1):2365405. doi:10.1080/07853890.2024.2365405.Willy K, Ellermann C, Reinke F, et al.The impact of cardiac devices on patients’ quality of life: a systematic review and meta-analysis.J Cardiovasc Dev Dis. 2022;9(8):257. doi:10.3390/jcdd9080257American Heart AssociationElectrocardiogram (ECG or EKG).Barold SS.Type I Wenckebach second‐degree AV block: A matter of definition.Clin Cardiol. 2018;41(3):282-284. doi:10.1002/clc.22874National Heart, Lung, and Blood Institute.What are pacemakers?MedlinePlus.Preventing heart disease.
9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.MedlinePlus.Heart block.American Heart Association.Heart conduction disorders.Karabag T, Kalayci B, Sayin MR, Erten T.Atrioventricular conduction defect associated with severe hyponatremia.Clujul Med. 2018;91(3):342-345. doi:10.15386/cjmed-846.Ata F, Khan HA, Choudry H, Khan AA, Tahir S, Cerqueira TL, Illigens B.A systematic review of the clinical characteristics and course of atrioventricular blocks in hyperthyroidism.Ann Med. 2024 Dec;56(1):2365405. doi:10.1080/07853890.2024.2365405.Willy K, Ellermann C, Reinke F, et al.The impact of cardiac devices on patients’ quality of life: a systematic review and meta-analysis.J Cardiovasc Dev Dis. 2022;9(8):257. doi:10.3390/jcdd9080257American Heart AssociationElectrocardiogram (ECG or EKG).Barold SS.Type I Wenckebach second‐degree AV block: A matter of definition.Clin Cardiol. 2018;41(3):282-284. doi:10.1002/clc.22874National Heart, Lung, and Blood Institute.What are pacemakers?MedlinePlus.Preventing heart disease.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
MedlinePlus.Heart block.American Heart Association.Heart conduction disorders.Karabag T, Kalayci B, Sayin MR, Erten T.Atrioventricular conduction defect associated with severe hyponatremia.Clujul Med. 2018;91(3):342-345. doi:10.15386/cjmed-846.Ata F, Khan HA, Choudry H, Khan AA, Tahir S, Cerqueira TL, Illigens B.A systematic review of the clinical characteristics and course of atrioventricular blocks in hyperthyroidism.Ann Med. 2024 Dec;56(1):2365405. doi:10.1080/07853890.2024.2365405.Willy K, Ellermann C, Reinke F, et al.The impact of cardiac devices on patients’ quality of life: a systematic review and meta-analysis.J Cardiovasc Dev Dis. 2022;9(8):257. doi:10.3390/jcdd9080257American Heart AssociationElectrocardiogram (ECG or EKG).Barold SS.Type I Wenckebach second‐degree AV block: A matter of definition.Clin Cardiol. 2018;41(3):282-284. doi:10.1002/clc.22874National Heart, Lung, and Blood Institute.What are pacemakers?MedlinePlus.Preventing heart disease.
MedlinePlus.Heart block.
American Heart Association.Heart conduction disorders.
Karabag T, Kalayci B, Sayin MR, Erten T.Atrioventricular conduction defect associated with severe hyponatremia.Clujul Med. 2018;91(3):342-345. doi:10.15386/cjmed-846.
Ata F, Khan HA, Choudry H, Khan AA, Tahir S, Cerqueira TL, Illigens B.A systematic review of the clinical characteristics and course of atrioventricular blocks in hyperthyroidism.Ann Med. 2024 Dec;56(1):2365405. doi:10.1080/07853890.2024.2365405.
Willy K, Ellermann C, Reinke F, et al.The impact of cardiac devices on patients’ quality of life: a systematic review and meta-analysis.J Cardiovasc Dev Dis. 2022;9(8):257. doi:10.3390/jcdd9080257
American Heart AssociationElectrocardiogram (ECG or EKG).
Barold SS.Type I Wenckebach second‐degree AV block: A matter of definition.Clin Cardiol. 2018;41(3):282-284. doi:10.1002/clc.22874
National Heart, Lung, and Blood Institute.What are pacemakers?
MedlinePlus.Preventing heart disease.
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