"You know, I discovered I had a heart murmur, the cardiologist says it's nothing serious but I'm equally worried"
What is the heart murmur, what risks does it have, when the problem should not cause any concern? To these and other questions we will try to answer in this article on the heart murmur.What is heart murmur?
The heart murmur is a term coined to describe a condition in which the flow of blood pushed by the contraction of the heart muscle loses the normal and characteristic silence.
In particular situations this flow can become whirling and generate a certain noise that can be easily heard with the phonendoscope.
Often this sound is completely devoid of pathological meaning; other times it hides even serious heart problems.
The heart as we know is a very efficient pump and therefore extremely sophisticated. The cardiac cycle consists of several phases, some in which the muscles relax and the valves close, others in which the myocardium contracts and the valve apparatus opens.
To understand what is meant by heart murmur, one should get to know the physiology and anatomy of the heart, a very complicated subject that will be treated only marginally in this article (for more information see: Heart: anatomy and physiology).
Causes of heart murmur
The heart murmur arises when there is an alteration, for example due to an obstacle, of the normal blood flow. There are an infinite number of situations in which this can happen, some of these are physiological and do not cause problems for the patient, others are dangerous for the health of the individual.
The heart murmur can for example be caused by what doctors call valvular insufficiency: a situation in which the valves that regulate the passage from atrium to ventricle and from ventricle to the bloodstream do not open or do not close perfectly. Heart valves have the important function of guaranteeing the passage of blood in a single direction. An incontinence of these anatomical structures causes a reflux through them that is perceived on hearing and diagnosed as a heart murmur from valve insufficiency.
In medicine for heart murmurs we mean cardiac noises generated by whirling motions of the blood flow, of longer duration than that of added tones and noises, generated by valve vibrations and normal or pathological vascular structures
Given the complexity of the cardiac cycle, one can easily imagine how many other types of heart murmur exist. They are classified according to the dynamics (systolic, diastolic, continuous or systolic-diastolic) to the intensity of the murmurs (six degrees in increasing order of gravity), to the hue (high, medium, low) and to the phonetic characteristics (aspirated, to roar, harsh, musical, a "seagull cry" etc.)
The anatomo-physiological alterations underlying the heart murmurs are numerous and very complex. Noises due to turbulent blood flow can in fact arise due to:
- stenosis (narrowing). Condition in which blood flow passes through the partial obstruction of a valve apparatus or arterial vessel (aortic, mitral stenosis, etc.)
- retrograde flow through insufficient valve. In these cases we speak of regurgitation breath in which the blood is sucked by an incontinent valve and instead of advancing forward it goes back (triscupid insufficiency, mitral valve etc.)
- flow in a dilated arterial vessel, for example in the case of an aortic aneurysm. Take as an example the aortic or semi-lunar valve that blocks the passage of blood in the arterial vessels until the ventricle is completely filled. If the aorta is excessively dilated the valve, despite being of normal size, fails to completely occlude the orifice which is crossed by a small amount of blood generating the breath
- flow through heart or vessel vessels. In these cases a little blood passes through small non-physiological holes. This is the case, for example, of the defects of the inter-atrial or inter-ventricular septum that normally divide the heart into two distinct halves, preventing any type of communication between the two atria and between the two ventricles
- increased flow in normal anatomical structures (ejection murmur in the presence of anemia, hyperthyroidism, stress, etc). In these cases the presence of the breath indicates a non-cardiac pathology
The mitral valve prolapse, to cite an example, is not a real heart murmur even if initially it can be perceived as such. The disease is in fact caused by the prolapse of one or both valvular flaps due to excess tissue and / or failure of tendon structures. This prolapse gives the valve a swollen sail appearance that protrudes into the atrium. In these conditions a typical noise is generated which is perceived as a shake (click) similar to that produced by a sail when it slams. For these reasons the valve is easily incontinent and this can generate a retrograde murmur perceptible at auscultation.
Benign breaths
The heart murmur can arise due to pathological anatomical alterations or simply due to abnormal flows from cardiac hyperactivity.
BENIGNI SOFFI are "physiological" puffs, rather common at a young age and which have nothing to do with a heart condition.
The passage of blood, driven by the contraction of the heart, in the large arterial vessels or in the other cardiac chambers (from atrium to ventricle) is constrained by the presence of valves that open and close in relation to the phase of the cardiac cycle. These valves have a reduced size compared to the heart chambers and this causes an increase in the speed of the blood flow passing through them.
This acceleration has repercussions on the anatomical structures crossed, which having a strong elastic component vibrate generating the noise that is at the base of the heart murmur. When this phenomenon becomes particularly intense (the blood flow increases) we speak of murmurs BENIGNI OR FUNCTIONALS. Some of these, in addition to having no pathological significance, are temporary and disappear when the conditions that generated them cease (excessive stress, anemia, fever, pregnancy, etc.).
Others, although expressing a slight valve malfunction, are considered entirely physiological.
In children the heart murmurs are very frequent (50-60%) and in the vast majority of cases they are classified as "innocent" or as breaths without pathological meaning. To say that a child has an innocent breath is therefore to say that his heart is perfectly healthy.
