What Is Heart Block?

Author: Jo Johnson

Heart block is a term given to a condition when the upper chambers of the heart do not send signals to the lower chambers of the heart properly or sometimes at all. In the upper chambers part of the anatomy is called the sinoatrial node (SA node), which triggers the electrical impulses through the upper sections of the heart and passes it to the atrioventricular node (AV node), which conducts the electricity through the lower chambers of the heart. Sometimes the communication between the two does not occur properly or is lost entirely, this is known as heart block. There are three classification of heart block depending on the severity of the signal transmission failure; these are called first, second and third degree heart block.

First Degree Heart Block

This type of heart block is diagnosed when the signals passing through the AV node occur more slowly than normal. It is quite common in those who are very fit, or as a side effect of certain medications. It is not normally serious and often no treatment is required as heart rate and rhythm are usually unaffected.

Second Degree Heart Block

Second degree heart block is divided into two further categories: type 1 and type 2. Type 1 of this group occurs when the signals are interrupted and slowed until they become more and more delayed until eventually the beat is skipped entirely. Although it can cause feelings of dizziness and faintness, it is not very serious and sometimes is left untreated. Type 2, is more serious as the signals from the upper chamber do not reach the lower chambers properly, slowing the heart rate so much so that often a pacemaker will need inserting to regulate the heart rate and keep it beating in a strong regular pattern.

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Third Degree Heart Block

The most serious form of heart block, it means the signals from the atria, do not reach the ventricles at all leading to a very slow heart rate and overall poorly functioning heart. It can be an emergency as the person is at risk of cardiac arrest and can also suffer from the consequences of dysfunction of the heart muscle. It is often a side-effect of heart disease but can be present at birth and is treated by the use of a pacemaker.

Signs and Symptoms

For those diagnosed with first degree heart block, there may be no obvious symptoms at all but as the condition becomes more serious leading into second and third degree, breathless, dizziness, chest pain and palpitations are likely.

Your situation may be slightly different. ask a question below ↓ and our editorial team will reply with our advice.

Diagnosis

Heart block can be diagnosed using one or all of the following tests: and electrocardiogram, which monitors the electrical activity in the heart, blood tests, a 24 hour tape, which records the heart beats over 24 hours, and echocardiogram, which involves visualising the heart under ultrasound scan or by using electrophysiology, which tests the conductivity of the heart tissue using tiny electrical impulses.

Risks of Heart Block

If heart block is serious, there is significant risk of suffering from a stroke or heart attack. Any symptoms relating to the heart must be professionally diagnosed and treated effectively in order to prevent more serious injury occurring.

Heart block can be both non-serious and require no active treatment, or it can be life threatening if left untreated depending on the type of heart block diagnosed. It is important to seek medical advice if any of the mentioned symptoms are experienced.

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7 questions

Ask Cardiac Matters a Question

rafa 24/03/2020 at 1:32 pm

Hello. I have born first degree heart block. 10 years ago was temporarily changing to 2 degrees, but stay first degree. Am I at high risk people coronavirus?

Poppypie1 23/01/2020 at 1:06 pm

Hi there I had a pacemaker fitted last year for Mobitz II heart block. My pacemaker is set to fire if my rate drops below 60 b/pm. Am I correct thinking that the pacemaker simply prevents bradycardia and is not an actual cure for heart block? Despite my cardiologist also finding a common congenital heart abnormality, a large atrial septal defect measuring 3cm with associated pulmonary hypertension and severely dilated right atrium & right ventricle, this was not felt to be attributable to my heart block. He feels I quite simply had two separate unrelated heart problems.
In addition to the pacemaker I’m also taking a small dose of a Betablocker (Bisoprolo 1.25mg) for troublesome atrial ectopics. Since I had my pacemaker I’ve been exceptionally tired with very poor exercise tolerance and breathless but my cardiologist has assured me at length they’re NOT related to heart block.
I’ve just had a CT coronary angiogram and CT calcium score performed on Monday as also found out I have familial hyperlipidaemia (cholesterol 8.6) and Lipoprotein(a) 210 nmols/L & started on Atorvastatin 40mg.
Does anyone else still feel ‘rotten' despite their pacemaker? I feel I’ve aged by ten years plus since having these issues; I’m so slow & sluggish due to tiredness and fatigue! I’m only 54! Any comments or suggestion will be respectfully received. Thank you.

James 28/10/2019 at 10:11 am

Hi I have a pacemaker following heart block. Doctors don't know what caused it and told me i should be just fine from now on (I'm only 57 years old).
1) I find it easy to get very good basic information about my condition (like your very clear web page) and there are medical textbooks that I can't understand but there isn't much in between - do you have any suggestions? I can understand science and statistics (A level biology, etc). Something like Sandeep Jauhar's excellent book "heart" but with a lot more detail?
2) Specifically i'm interested in long term (25 year?) prognosis of pacemaker patients, and whether heart block is linked to other heart diseases. (Since the pacemaker I've got hypertension too).

CardiacMatters Editor 04/07/2018 at 11:28 am

Thanks for sharing your experiences, we can't give individual medical advice here but perhaps one of your our readers has had a similar experience and can post here.

Ronscams 03/07/2018 at 8:12 am

Hi there I'm currently 42 years old and have been having dizziness feeling faint when standing up after sitting down . Also I've noticed I've been a lot less active feeling fatigued , very tired and have palpitations sweating for no reason ( bit like panic attack ) . 12 years ago I face planted the floor passed out I didn't even know what happened until I came round and was told what had happened . I never thought anything of it until a few month after when I cut my hand open and cut the nerve to my thumb I had it fixed and had to have physiotherapy I went to my first appointment and same thing happened i was told to see my GP after speaking to GP I had a monitor rigged up and had to keep it on at all times for 2 weeks . The results came back and I had same letter as GP and I recall it saying I was somewhat bradacardic heart rate as low as 36 beats a minute . I was told it's common in highly trained athletes and i will live longer . So I've been bragging to everyone saying I'm as fit as a top athlete and will live longer which I thought was weird but you tend to believe doctor's in hospital . Well I'm not highly trained nor an athlete and i left it there until now as ive been thinking hard to why I was gradually finding it very hard to do day to day things even missing important appointments , meetings not getting child to school on time , I Lost my building maintenance business due to gradually getting less and less jobs done as i usually would over the span of few years . I sometimes can't find the energy to keep myself clean and keep house clean or make meals , put washing machine on and feeling out of breath going up stairs and getting pins and needles more often in left hand sometimes having dead leg to point I can't feel it when I go to stand and have sprained ankle alot as a result of it . I'm slim built 42years old and know I shouldn't be experiencing Any of this it's like I'm a really old person even my dad at 60 is more active and has way more energy . So I've come on here looking for information or advice on what to do as i dont want to bother GP or hospital incase its nothing .
Ps. Also had gear fit 2 wrist watch which records heart rate and i noticed it was below 60 more than being above 60 which brought memory bk from 12 year ago and prompted me to find out if slow heart can make you less active and now writing this . Please accept my apologies for long message only wanted to try give as much info as possible . I hope someone can help and thank all inadvance much appreciated.

Kind Regards
Aaron woods

Win 02/07/2018 at 10:53 am

I sometimes get a tingling sensation in my left hand when I hold it up in the air i.e.reading in bed.otherwise I am very fit although I am 82

Jolly Gee 27/02/2018 at 11:52 am

Is a tingling sensation which occurs in the face and neck, arms, torso and even the whole body a symptom of anything to do with the heart, blood pressure etc? Does anybody else experience this?

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