ABSTRACT
Stress has been defined in many ways as a state of psychological arousal that results when the external demand is beyond what one can cope with. Stress is caused by various factors called stressors. Medical students are subjected to different kinds of stressors, such as pressure of academics with obligation to succeed, an uncertain future and difficulties of integrating into the system and different teaching protocols, which may affect their learning ability and performance. Stress has a great impact on brain mainly in the form of impaired memory and on cardiovascular function in the form of increased heart rate and blood pressure. The study was planned to assess the effects of examination induced stress on memory and blood pressure. The study was longitudinal in nature conducted at Department of Physiology, Santosh Medical College, Ghaziabad, India. Initially 100 subjects were selected from 17-24 years of age group then all the subjects were divided into two groups of 'slow-learners' and 'fast-learners' based upon their past academic performances. Readings were taken at two stages of academic year, 05 months before pre-prof examination and 03 days before pre-prof examination. Blood Pressure were measured and the memory assessments were done by using 10 subtests of PGI memory scale. We found a significant increase in stress level 3 days before the examination, compared to 5 months before the examination which in turn affected both blood pressure and memory functions. But, slow-learners were affected more compared to fast-learners.
ABSTRACT
BACKGROUND: The cold pressor test (CPT) is a recognized physiological technique to evaluate autonomic cardiovascular function. The present case study assessed the cardiovascular response of a healthy adult male during 3 min of CPT. METHODS: Heart rate (HR) by single-lead electrocardiography and blood pressure (BP) by an arterial tonometer of the participant on a beat-to-beat basis were recorded before and during CPT. RESULTS: HR during CPT showed a biphasic pattern with an initial increase from baseline (86 bpm) to the first 30 s of CPT (93 bpm) followed by a decrease. It dropped to 51 bpm during the last 30 s of CPT. Systolic blood pressure (SBP) increased from baseline (110 mmHg) to 1 min (122 mmHg) followed by a decrease. SBP immediately after CPT reduced to 57 mmHg. Diastolic blood pressure (DBP) from baseline (71 mmHg) slightly increased to 75 mmHg up to 90 s of the test, thereafter it registered a fall, and during the last 30 s of CPT, DBP fell to 30 mmHg. Stroke volume increased from baseline (75 mL/min) to the first 30 s (99 mL/min), followed by a slight reduction which was maintained till last of the test (70 mL/min). Cardiac output after an initial increase from baseline (6.4 L/min) to the first 30 s (9.2 L/min) decreased to 4.1 L/min during the last 30 s of the test. Baroreflex sensitivity (BRS) from baseline (9.32 ms/mmHg) plummeted to 6.67 ms/mmHg during the first 30 s of CPT followed by an increase, and after CPT, BRS was increased to 15.23 ms/mmHg. Other cardiovascular parameters such as myocardial contractility (dp/dt), total peripheral resistance, and mean arterial pressure were reduced in the individual at the time of loss of consciousness that occurred at the end of the last 30 s of CPT. CONCLUSIONS: The present case study described the modulation of cardiovascular functions of a healthy male during CPT, which finally led to the development of neurocardiogenic syncope characterized by hypotension and bradycardia.