: Endocarditis, therapy and prophylaxis
Mitral insufficiency
fficienza mitralica
La stenosi
aortica
It means that the valve is insufficient, ie at the time of systole or contraction of the right ventricle, since the valve is located between right atrium and right ventricle (see anatomy of the heart), blood, rather than proceeding to the pulmonary artery, partly regurgitation through the insufficient valve (so to speak incontinent and flattened) and returns to the overlying atrium, with consequent stasis of the venous systemic circulation and possibility, in the most severe cases, of liver and liver stasis "nutmeg", known as condition of "cardiac cirrhosis" or of stasis liver ". Since the venous system of the head is also discharged through the jugular, in the succlavias and in the upper cavity and in the right heart, the impeded discharge pressure is manifested by the jugular turgidity. The most common cause of IT is functional, related to dilatation of the right ventricle, resulting in a flattening of the tricuspid annulus. This is due to multiple possible causes: mitral valvulopathy, congenital heart disease, right ventricular infarction, pulmonary hypertension and pulmonary heart. Among the possible organic primitive causes of IT we remember those congenital: Ebstein anomaly, partial ventricular atrium channel, mitral prolapse; and those acquired: rheumatic vice, infarction with papillary muscle injury, trauma, infective endocarditis, carcinoid syndrome.
It's generally well tolerated in the absence of pulmonary hypertension. When this occurs, the cardiac output decreases and the clinical manifestations typical of the right ventricular failure appear, with an increasing trend. Therefore these patients have marked hepatomegaly, peripheral edema and considerably dilated jugular veins (see photo). On examination, the jugular veins are dilated and there is a prominent V wave followed by an accentuated collapse. In the left parasternal the right ventricular impulse, hyperdynamic and sometimes along the lower right margin of the sternum, a systolic pulse produced by the enlarged right atrium can be perceived.
Listening to it, a holosystolic murmur is more easily audible at the fourth
intercostal space in the left parasternal or in the subxifoidal area. When the
right ventricle is greatly enlarged and occupies the anterior surface of the
heart, the breath is better audible to the tip and can easily be confused with a
finding from mitral insufficiency. The puff of IT increases during inspiration (Carvallo
maneuver); but when, due to the right ventricular failure, the increase in the
right ventricular filling can not further increase the systolic throw, the
inspiratory accentuation of the breath is not evident. In these cases the
erected station with consequent reduction of venous return, can again bring out
the variation of the breath with the breath acts. In addition, the breath
increases in intensity with the Muller maneuver (forced inhalation to closed
glottis) with exercise and with inhalation of amyl nitrite. It is reduced
instead of intensity and duration in an upright position. Frequent is the
finding of a third tone originating from the right ventricle which is
accentuated with inspiration. Increased atrioventricular flow may cause audible
protodiastolic murmur to the tricuspid focus.
On radiological examination, a marked cardiomegaly due to dilatation of the
ventricle and of the right atrium is evident in anterior anesthesia, with
enlargement at the expense of the right and left transverse hemidiameter, with
the tip at the top. The role of angiography in the diagnosis and quantification
of LT is somewhat controversial. In fact the contrast medium injected by
catheter, in right ventricle can create false positives since the regurgitation
of this medium in the left atrium could be linked to the fact that the catheter
passing through the valve prevents its perfect closure. At echocardiography, we
can highlight the enlargement of the right ventricle with increased Chinese and
paradoxical movement of the interventricular septum linked to the volume
overload. In patients with IT secondary to right ventricular dilatation and
pulmonary hypertension the pulmonary valve presents reduction or absence of the
"a" wave. A possible prolapse of the tricuspid can easily be diagnosed with the
echocardiographic examination and shows characteristics quite similar to those
of mitral prolapse.
The rapid injection of 10-20 cc of saline into a peripheral vein causes the
small two-dimensional echo to show small bubbles that in the case of IT present
a movement of the air coming through the tricuspid valve. IT in the absence of
pulmonary hypertension does not require surgical treatment, while in the case of
pulmonary hypertension there is considerable benefit from the surgical
intervention with the Carpentier ring implant. In patients with IT associated
with mitral valvulopathy and pulmonary hypertension, behavior is different
depending on the degree of tricuspid regurgitation assessed by palpating the
valve during surgery. In cases of mild IT, no surgical treatment should be
performed. In the case of medium-sized IT, good results are obtained with the
anuloplasty according to De Vega or with the Carpentier ring. Less clear is the
line of conduct to be taken in case of severe IT: some surgeons perform the
anuloplasty, others the valve replacement. Organic IT, due to rheumatic disease
or endocarditis, in most cases requires valve replacement. In these cases, due
to the high incidence of thrombotic events related to the mechanical prosthesis
in this area (low pressure and flow velocity), it is preferable to implant
porcine biological prostheses.
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