Early Detection of Heart disease

Case history

A seemingly healthy 52 year man turned up to my outpatient clinic late afternoon for a blood test and electrocardiogram (ECG) in preparation for consultation with me scheduled three days later. His GP had referred him the day before because he had some mild chest tightness during and after a recent game of tennis.

Fortunately our experienced cardiac nurse questioned him while taking the ECG and popped her head around my door during the packed clinic to ask whether he should have an urgent assessment. My clinic was already running late so I suggested he went straight onto our exercise treadmill ECG – often used to triage such situations by testing the coronary artery capacity to handle exercise. A few minutes later I dropped in to see him and get the story.

In essence he was completely well until four days before, when he had experienced some ‘indigestion-type’ chest discomfort while playing his regular game of tennis (singles)- and then again a few days later while walking. He had also experienced one episode at rest lasting a few minutes since. He mentioned that he had also experienced tremendous flatulence resembling indigestion. I noticed that his ECG showed a minor abnormality, but was reassured that his troponin blood test was normal however his exercise test a few minutes later showed only mild abnormalities during the recovery period. Without this particular story the virtually normal treadmill ECG might have given false reassurance.

It seemed to me however that the combination of a recent history of new cardiac sounding symptoms associated with mild ECG abnormalities was cause for concern since together they indicating a diagnosis of ‘unstable angina’. I felt he should therefore be triaged to ‘high risk’ and thus interrupted clinic to see him and his wife. A few minutes later they were both sitting in my office while I explained the need for immediate medication (aspirin, clopidogrel and betablockers) and hospital admission for coronary angiography in order to confirm what we suspected - a severe narrowing (stenosis) of one of the three main coronary arteries feeding his heart.

During the five minute consultation he started to look unwell, developed some mild chest pains- and a few moments later collapsed on the floor. He had become terrifically pale and was sweating profusely. His blood pressure was barely measurable and heart rate was very slow. I raised his legs up onto a chair to help lift his blood pressure, pressed the emergency bell and two nurses rushed in to help me resuscitate him with some intravenous medication and fluids while an ambulance was summoned: fortunately by the time the paramedic crew arrived a few minutes later, the treatment had worked and his systolic blood pressure had risen from a dangerously low 60 mmHg to 100 mmHg.

The patient was driven at speed directly to the emergency catheter lab six miles away where he was received by the expert ‘heart attack’ team. The paramedic crew had taken another ECG in transit, showing that he was in the process of having a ‘heart attack’, and the coronary angiogram taken a few minutes later, confirmed this since his right coronary artery had completely blocked with a large fresh blood clot that had formed over a ruptured fatty atheromatous deposit. It took my colleague a further few minutes to clear it by passing a wire down the artery and inserting several stents. By the time my outpatient clinic finished that evening the patient was sitting up in bed in coronary care feeling back to normal and asking for something to eat.

He was going to make a complete recovery.

RCA.gif

This image shows a right coronary artery filled with Xray contrast (in black) that illustrates the narrowing (Stenosis) responsible for the heart attack.

Comment

This case illustrates how quickly a heart attack can happen. In his case it is very likely that a fatty deposit (plaque) located in the wall of his coronary artery ruptured during the game of tennis a few days before causing a temporary interruption of arterial blood feeding his heart. Fortunately the blood flow must have been restored by the action of his own natural blood anticoagulants and ‘clot-buster’ systems, because his symptoms cleared without any medical intervention. A few days later these protective systems failed and his artery had blocked. Many people may not be fully aware that the balance between an artery blocking and staying open can often be precarious, as in this case, where the exercise test was the ‘final straw’ and provoked a blockage (occlusion) leading to this patient’s collapse.

Timely intervention saved his life. Had the occlusion occurred at home, gym or in the car, the story might have had a different ending.

The main point of this story however is that although this patient developed symptoms for only a few days before his heart attack, his coronary artery disease would have been present for many years. At the time of his angiogram my colleague found that although just one small area in one of his three vessels had ruptured causing the recent symptoms, other areas of fatty deposits were also visible.

It is well known that these plaques can take many years to develop. In fact the first signs of the disease can be seen in susceptible people as young as their early twenties, where ‘fatty streaks’ can be found on the inside surface of the coronary arteries. These so- called ‘fatty streaks’ develop into fatty deposits within the wall of the coronary vessels which evolve into more dangerous plaques that can either gradually enlarge to create a pinch point (narrowing or ‘stenosis) which limits the blood flow within the whole vessel - causing angina of effort, or which alternatively mature into focal deposits where the vessel wall is replaced with more liquid plaque (resembling toothpaste in consistency) liable to unpredictable rupture- which can unfortunately cause a sudden large blood clot that interrupts arterial blood flow to the hear muscle, as happened in this case.

It is important to realise that these fatty plaques need to block by at least 50% of the artery diameter before they even begin to show up on routine screening tests such as stress echocardiograms, nuclear myocardial perfusion scans and exercise stress ECGs. In addition symptoms of angina (chest tightness on effort) or breathlessness occur may not appear until one or more short sections have pinched or narrowed to reduce diameter of the artery by over 75%.

Coronary artery disease is caused by clogging up of the arteries but chest pain symptoms may not occur until the disease is very advanced.

After a ‘near miss’, cardiologists are often asked whether there might have been any way of finding out that there was a problem before the heart attack occurred- after all if the condition takes years to develop then logically were it possible to detect early cases, prevention measures might be undertaken.

The short answer is ‘yes’, coronary artery disease can be detected many years before it causes symptoms. Although public health care prevention programs already exist to help identify high risk cases based on epidemiology and presence of known risk factors- for example people with multiple risk factors such as smoking, high blood pressure, diabetes and raised cholesterol have a much higher rate of heart disease, yet patients with multiple risk factors constitute only a small proportion of the UK population at risk- and therefore most heart attack victims do not have multiple risk factors.

It is thought that this curious statistic is due to two facts:

1/ Scientists estimate that roughly half of heart disease cannot be explained on the basis of standard risk factors - therefore is prediction based on risk factor analysis accurate. Take into account that heart attacks, like the weather occur on a probability basis.

2/ Only a very small proportion of the population in the UK have multiple risk factors and are massively outnumbered by people with few risk factors who collectively therefore have the majority of heart attacks and angina.

It is clear that there is a need to detect disease at the earliest opportunity and this is the basis on which increasing numbers of Cardiologists around the globe are recommending routine Cardiac CT screening should be considered in apparently healthy people before any symptoms develop. 

The Haste and Haste Academy Charities are planning to raise profile and funding for thsi important cause.

This blog is an exercpt of the author's book chapter on Coronary Calcification 'The Naked Heart' published by Green Pages Publication

 



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Edward Leatham is a Consultant Cardiologist in Surrey and a Trustee of Haste and Haste Academy.

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