Purpose, evaluation and critique PHA is an acronym that stands for the peripheral heart action training which deals with the analysis of the heart by approaching it through the body blood circuitry. This form of training became popular in the 1960s and was meant to ensure that blood circulation is uniform and occurs throughout the body. The training begins by attending to the heart’s smaller muscles before extending to the larger muscles in the rest of the body. I totally agree with the author since this is a medically friendly way of controlling the pulmonary system as well as a deadly precautionary action against circulatory problems. However, I think that this process is rather selective as it has no room for weak patients (Dirksen, 2011). The author describes thromboembolism as a lung disease that affects the parenchymal cells of the lungs. He presents the results of a research initially carried out to find out how different patients respond to extreme vasodilator challenge with EPO, CCB and ITSS. The different patients were exposed to baseline, EPO, CCB and sildenafil 25 mg conditions during the experiment. The activities performed on the patients include; performing a chest x-ray, letting the patients walk approximately six minutes in a room with normal oxygen concentration, carrying out tests on the patients overnight, and testing the functionality of their pulmonary and lung air supply. This was then supplemented by other practices such as echocardiographic tests. The results of these tests were then collected, analyzed and recorded. It was established from the data that the baseline condition exposes patients to the highest pulmonary pressure and pulmonary artery pressure. Patients exposed to sildenafil 25mg condition recorded the lowest pulmonary artery pressure while those exposed to CCB recorded the lowest pulmonary pressure (Burger & Murali, 2008). The cardiac response was higher among patients under the influence of sildenafil 25mg and lowest in the baseline condition while the baseline condition recorded the highest pulmonary vascular resistance while sildenafil 25mg recorded the lowest. This data is useful to nurses as it indicates different ways in which the human heart and the entire circulatory system respond when exposed to different conditions which can then be used to offer prescriptions and safety precautions to patients. Doctors may also find it useful in advising the patients with respect to places they should visit and those they should not and how frequently they should visit the selected places (Burger & Murali, 2008). However, I find a similar weakness as in PHA which is its mechanical nature. Hemodynamic response Purpose, evaluation and critique A second experiment was carried out on patients with vasoreactivity. The main objective of this research was to find out how they react to echocardiographic exposure and exercise in follow-up. Different WHO classes of patients under test were instructed to have a six minute walk and the tested parameters were recorded in a table as the one shown below (Burger & Murali, 2008). Time      WHO class  6 minute walk distance  Right ventricular systolic pressure  Mean pulmonary artery pressure  Right ventricular changes  Therapy                 O months  III        532                     51                                   37                              FX