This study demonstrates that in patients with AS and AR, the LA has a similar behavior and that exist a close correlation between LA volumetric and functional parameters. The variable mainly associated with PH was LA strain of reservoir phase.

Sudden cardiac arrest (SCA) and sudden death (SD) continue to be a global public health problem, although the true incidence is unknown, it is estimated that they are responsible for 30% of cardiac origin mortality and may represent 20% of total mortality in adults. Unfortunately, the majority of cases occur in the general population, at the out-of-hospital level, in homes and in people who were not known to have heart disease. Although the majority of SCA victims are considered to be of cardiac origin and more frequent ischemic, it is not possible to rule out other causes only with the clinical diagnosis. Autopsy, histological, and toxicological studies are necessary in all victims of SCA and SD to determine the precise cause of death; when these studies are carried out, causes of non-cardiac origin have been found in up to 40% of victims. The type of arrhythmia responsible for an episode of SCA and SD has changed over the years, now asystole and pulseless electrical activity are detected more frequently than ventricular fibrillation or pulseless ventricular tachycardia. These and other aspects that we consider important in the current behavior of SCA and SD are analyzed in this article.

Platypnea orthodeoxia syndrome (POS) is a clinical entity described in the middle of the last century. It is characterized by dyspnea and hypoxemia triggered by standing and relieved with recumbency. The diagnosis is predominately clinical. The degree of hypoxemia is variable; however, the diagnostic criteria include the decrease in arterial oxygen pressure more than 4 mmHg or oxygen saturation more than 5%. Even though many diseases cause this syndrome, there are only two responsible mechanisms, intracardiac, and intrapulmonary shunts. The coexistence of diverse structural and physiological abnormalities joined to gravitational forces that induce blood shunt after standing is crucial in each mechanism. The intracardiac mechanism is characterized by right to left blood shunt through atrial septal communications and, the right atrium pressure could be normal or increased. In addition, some patients have one or more coexistent aortic, spinal, or intracardiac alterations. The intrapulmonary mechanism is less frequent and is caused by parenchymal or vascular pathologies. Transthoracic echocardiogram is the first diagnostic modality; however, understanding the pathophysiology is the key for a rational diagnostic approach and subsequent diagnostic studies. Treatment is possible and effective in the majority of intracardiac mechanisms and some intrapulmonary. This review focuses on the pathophysiologic mechanisms of POS and their diagnostic workup.

Platypnea orthodeoxia syndrome (POS) is a clinical entity described in the middle of the last century. It is characterized by dyspnea and hypoxemia triggered by standing and relieved with recumbency. The diagnosis is predominately clinical. The degree of hypoxemia is variable; however, the diagnostic criteria include the decrease in arterial oxygen pressure more than 4 mmHg or oxygen saturation more than 5%. Even though many diseases cause this syndrome, there are only two responsible mechanisms, intracardiac, and intrapulmonary shunts. The coexistence of diverse structural and physiological abnormalities joined to gravitational forces that induce blood shunt after standing is crucial in each mechanism. The intracardiac mechanism is characterized by right to left blood shunt through atrial septal communications and, the right atrium pressure could be normal or increased. In addition, some patients have one or more coexistent aortic, spinal, or intracardiac alterations. The intrapulmonary mechanism is less frequent and is caused by parenchymal or vascular pathologies. Transthoracic echocardiogram is the first diagnostic modality; however, understanding the pathophysiology is the key for a rational diagnostic approach and subsequent diagnostic studies. Treatment is possible and effective in the majority of intracardiac mechanisms and some intrapulmonary. This review focuses on the pathophysiologic mechanisms of POS and their diagnostic workup.

No abstract