Related by context. All words. (Click for frequent words.) 59 vasomotor 58 hyperreflexia 58 expiratory 57 myocardial contractility 57 autonomic dysfunction 57 electrophysiologic 57 tissue oxygenation 56 cerebral oxygenation 56 parkinsonian 56 rate variability HRV 56 hyperacute 56 orthostatic 56 induced cardiomyopathy 56 cardiopulmonary disorders 55 baroreflex sensitivity 55 variant angina 55 tachyarrhythmias 55 syndrome OSAS 55 palpitations shortness 55 neuro endocrine 55 oxygen saturation SpO2 55 bronchial hyperresponsiveness 54 tachypnea 54 procedural sedation 54 respiratory humidification 54 atrioventricular block 54 sensory disturbances 54 obstructive sleep 54 nasal polyposis 54 dysrhythmias 54 hypercapnia 54 repolarization 54 dyspnoea 54 Paroxysmal 54 lethal arrhythmias 54 ventilatory 54 apneic 53 spirometric 53 Atrial fibrillation AF 53 obstructive pulmonary disease 53 theta rhythm 53 PLMs 53 mucosal inflammation 53 affective psychoses 53 Sleep disturbances 53 exhaled NO 53 Obstructive sleep apnea OSA 53 dizziness nausea headaches 53 impaired cognition 53 syncope fainting 53 ataxic 53 acute ischemia 53 Diabetic neuropathy 53 ictal 53 hyperresponsiveness 53 asystole 53 thrombo embolism 53 chronic renal insufficiency 53 multifactorial disease 53 hyperarousal 53 pulmonary inflammation 53 nausea emesis 53 rhythm disturbances 53 Untreated sleep apnea 53 Tasigna prolongs 53 comorbid anxiety 53 skin conductance 53 levodopa induced 53 akinesia 53 Tachycardia 53 heart palpitations shortness 53 silent ischemia 53 light headedness dizziness 52 torsade de pointes 52 extrapyramidal 52 hypoventilation 52 neurologic impairment 52 laryngospasm 52 hypothalamic pituitary axis 52 artery stenosis 52 Diastolic 52 hypothalamic pituitary adrenal axis 52 somatosensory evoked potentials 52 Cheyne Stokes 52 ischemia induced 52 cerebral perfusion 52 comorbid depression 52 autoregulation 52 tracheal intubation 52 tachyarrhythmia 52 sinus node 52 hypoperfusion 52 cerebral oxygen saturation 52 hyperalgesia 52 organ perfusion 52 hypoxia induced 52 hypoxemia 52 neurohormonal 52 ionotropic 52 depressive symptomatology 51 physiological abnormalities 51 intravascular hemolysis 51 myocardial function 51 serum bicarbonate 51 mechanical dyssynchrony 51 alexithymia 51 atrial tachyarrhythmias 51 cardiac abnormalities 51 myoclonus 51 diaphoresis 51 Ventricular fibrillation 51 hypoxic ischemic encephalopathy 51 hypovolemic shock 51 vagal 51 ventilation perfusion 51 dizziness numbness 51 heart arrhythmias 51 alkalosis 51 hyper excitability 51 hemodynamically stable 51 psychophysiological 51 psychomotor agitation 51 affective psychosis 51 hemodynamic instability 51 psycho physiological 51 bronchodilatory 51 vascular cognitive impairment 51 anterior temporal 51 nausea vomiting dizziness 51 cardiogenic pulmonary edema 51 bronchoalveolar lavage 51 supraventricular arrhythmias 51 catecholamine 51 neurosensory 51 arterial oxygen saturation 51 abnormal clotting 51 intracerebral haemorrhage 51 neurologic symptoms 51 cortisol secretion 51 myocardial ischaemia 51 CP CPPS 51 rCBF 51 valvular heart disease 51 Hemodynamic 51 SIADH 51 afib 51 cerebral ischemia 51 CFQ R 51 capillary permeability 51 oxygen desaturation 51 prehospital setting 51 blood oxygenation 51 dizziness nausea confusion 51 rhythm abnormalities 51 Eisenmenger syndrome 51 arrythmias 51 myocardial ischemia 51 jugular venous 51 electroencephalographic 50 Electrophysiological 50 ventricular tachycardia VT 50 psychobiological 50 agitation hallucinations 50 pulmonary arterial 50 endotoxemia 50 coronary occlusion 50 glucocorticoid induced 50 glucocorticoid hormones 50 systolic diastolic 50 oculomotor 50 pulmonary infiltrates 50 depression suicidal ideation 50 cardiogenic 50 electrocardiographs 50 PLMS 50 severely impairs 50 inspiratory 50 polyuria 50 pulmonary artery hypertension 50 pharmacologically induced 50 cerebral vascular accident 50 cardiac troponin 50 dizziness lightheadedness 50 emotional reactivity 50 postoperative AF 50 Claudication 50 airway hyperresponsiveness 50 dizziness shortness 50 inotropic 50 dyssynchrony 50 comorbid psychiatric 50 irritability headaches 50 microvessel 50 Cardiac arrhythmias 50 sinus tachycardia 50 cough dyspnea 50 plethysmography 50 hyperthermic 50 autonomic nervous 50 middle ear effusion 50 inhibitory neurotransmitters 50 hypopnea 50 subsyndromal 50 Orthostatic hypotension 50 hypovolemia 50 inhaled corticosteroid therapy 50 salivary cortisol 50 ototoxic drugs 50 ventral prefrontal cortex 50 muscle rigidity 50 postural stability 50 predisposing factor 50 myocardial fibrosis 50 airway narrowing 50 CSF biomarkers 50 splanchnic 50 hypopneas 50 esophageal reflux 50 neurophysiologic 50 endogenous opioid 50 COPD emphysema 50 cardiac conduction 50 diaphragmatic 50 baroreflex 49 COPD exacerbation 49 HF hospitalization 49 microcirculatory 49 thrombo embolic 49 expiratory volume 49 abnormal heartbeats 49 cerebral vascular 49 vasoactive 49 esophageal motility 49 utero exposure 49 chronic obstructive airway 49 trigeminal 49 carotid atherosclerosis 49 neurologic dysfunction 49 asthma emphysema bronchitis 49 cTnT 49 obstructive airway disease 49 upregulating 49 tremors slowness 49 cardioembolic stroke 49 noxious stimuli 49 ventricular tachycardias 49 cognitive perceptual 49 corticospinal 49 physiologic responses 49 cardiac tamponade 49 isolated perfused 49 vomiting constipation 49 neurologic complications 49 antiphospholipid syndrome 49 carotid plaques 49 ventricular tachyarrhythmias 49 mental fogginess 49 symptomatic intracranial 49 Daytime sleepiness 49 unstable angina chest 49 arterial calcification 49 Excessive daytime sleepiness 49 Atrial flutter 49 nasal blockage 49 electroencephalograms 49 interindividual variability 49 fibrin deposition 49 prognostic significance 49 hypothalamic pituitary 49 polymorphic ventricular tachycardia 49 Norepinephrine 49 dominantly inherited 49 nociception 49 ventricular repolarization 49 poststroke 49 prefrontal cortical 49 cardiac infarction 49 clinicopathological features 49 hyperexcitability 49 albumin excretion rate 49 system dermatological GI 49 electrophysiological 49 antiphospholipid antibodies 49 dysphasia 49 neuritic 49 Visual Analogue Scale VAS 49 pressure natriuresis 49 muscle twitches 49 Skin rashes 49 metabolic dysfunction 49 status epilepticus 49 hypertension diabetes mellitus 49 airflow limitation 49 anticipatory anxiety 49 ICD shocks 49 pupillary 49 apneic episodes 49 rhinorrhea 49 colic diarrhea 49 gastrointestinal disturbances 49 dizziness heart palpitations 49 auditory stimulation 49 potentiation 49 hyperglycaemia 49 stridor 49 ejection fraction EF 49 hemodynamic measurements 49 cardioplegic arrest 49 aortic stiffness 49 Respiratory syncytial virus 49 cervicitis 49 irritability depression 49 fatigue shortness 49 cardiac dysfunction 49 ventricular arrhythmia 49 rhythmicity 48 plasma lipids 48 GABAA receptors 48 diabetic polyneuropathy 48 locomotor activity 48 euthymic patients 48 Holter monitoring 48 intracranial hypertension 48 thyroid carcinoma 48 somnolence sedation 48 Neurons communicate 48 forced expiratory 48 myocarditis inflammation 48 peripheral insulin sensitivity 48 intraventricular 48 obstructive coronary 48 erythema nodosum 48 IntroductionThe 48 diastolic pressures 48 Dilated cardiomyopathy 48 vagal tone 48 beta adrenergic receptor 48 hemodynamic parameters 48 cerebral arteries 48 baroreceptor reflex 48 Aortic stenosis 48 cortical atrophy 48 somatic symptoms 48 uninterrupted chest compressions 48 SGRQ 48 neurological abnormalities 48 gait disturbance 48 headaches nausea vomiting 48 pathophysiologic 48 circadian genes 48 postural instability 48 threatening arrhythmias 48 correlated inversely 48 premorbid 48 nociceptors 48 cardiomegaly 48 respiratory gastrointestinal 48 carcinomatosis 48 vasopressor 48 eNO 48 mesolimbic 48 upper airway obstruction 48 diathesis 48 headaches nausea fatigue 48 retinal nerve 48 oxygen saturations 48 Acetylcholine 48 physiological reactions 48 endothelium dependent 48 cardiac autonomic 48 tremors convulsions 48 acute myocarditis 48 pulmonary capillary wedge 48 renal tubular 48 esophageal manometry 48 EKG electrocardiogram 48 NYHA classification 48 psychosocial variables 48 dermatologic reactions 48 delayed gastric emptying 48 neovascularisation 48 coronary ischemia 48 systolic dysfunction 48 urodynamic parameters 48 atelectasis 48 nonischemic 48 gamma oscillations 48 acute aortic dissection 48 unstable cardiopulmonary 48 electrical conduction 48 incoordination 48 irregular quivering 48 hyperlipidaemia 48 galvanic skin response 48 aortic atherosclerosis 48 hemodynamics 48 edema swelling 48 blood oxygen saturation 48 perseverative 48 clinicopathological 48 phenotypic expression 48 nervousness irritability 48 cardiac contractility 48 herpetic 48 daytime alertness 48 heart palpitations dizziness 48 chemosensory 48 Genetic predisposition 48 inhaled anesthetics 48 respiratory 48 PaO 2 48 untreated OSA 48 acute myocardial infarction congestive 48 depression suicidality 48 myocardial infraction 48 bronchial spasms 48 tardive dyskinesia TD 48 Optic nerve 48 Sleepiness 48 metabolic acidosis 48 swallowing disorders 48 intraocular pressure IOP 47 dysphonia 47 inhalational 47 adrenocortical 47 NSAID induced 47 neuro transmitters 47 tension pneumothorax 47 acute decompensation 47 ischaemia 47 bile reflux 47 endocrinologic 47 granulomatous 47 receiving XGEVA 47 PLX STROKE targeting 47 expiratory flow 47 retinal vascular 47 coronary artery atherosclerosis 47 urogenital tract 47 Fibromyalgia Impact Questionnaire 47 #q# deletion syndrome 47 etiologic 47 lesional 47 neurotransmitter norepinephrine 47 hemorrhagic cystitis 47 obstructive apnea 47 haemodynamic 47 Viral infections 47 Symptom severity 47 vertebrobasilar 47 vessel dilation 47 creatine kinase MB 47 fever chills nausea 47 atopic disorders 47 thrombocytosis 47 physiological arousal 47 upregulates 47 mitral annular 47 allergic airway 47 gastric mucosa 47 chronic thromboembolic pulmonary 47 thermoregulatory 47 disordered breathing 47 reproductive endocrine 47 coughing wheezing shortness 47 reticular formation 47 plasma creatinine 47 intermittent hypoxia 47 gross hematuria 47 diastole 47 shortens systolic ejection 47 Epileptic seizures 47 emphysema bronchitis 47 airway obstructions 47 dissociative symptoms 47 ischemic vascular 47 arousals 47 submaximal 47 fractional shortening 47 nasal obstructions 47 idiopathic pulmonary 47 hypotensive 47 fatal arrhythmias 47 delirium convulsions 47 causative pathogens 47 inhaled irritants 47 mucociliary 47 fever cough shortness 47 inappropriate antidiuretic hormone SIADH 47 expressive aphasia 47 excessive salivation 47 disseminated intravascular coagulation DIC 47 primary ciliary dyskinesia 47 valvular disease 47 venous thromboembolic disease 47 headache dizziness nausea 47 vascular reactivity 47 tiredness shortness 47 atopic sensitization 47 pineal 47 constipation nausea 47 hormonal endocrine 47 elevated prolactin 47 interobserver agreement 47 ANCA associated 47 serum estradiol 47 GBA mutations 47 electrically stimulating 47 dyspnea shortness 47 intestinal permeability 47 akinetic mutism 47 comorbid disorders 47 Parkinson disease multiple sclerosis 47 androgen excess 47 nitric oxide synthase NOS 47 leptin deficiency 47 contractile function 47 hypersecretion 47 leukocyte counts 47 beta1 integrin 47 normoxic 47 Leydig cell 47 apneas 47 striatal dopamine 47 cardiomyopathies 47 dizziness blurred vision 47 methacholine 47 skin rashes diarrhea 47 acutely decompensated congestive heart 47 allergic eczema 47 Genetic mutation 47 da mage 47 pulmonary dysfunction 47 psychomotor retardation 47 tooth decay gum 47 oxyhemoglobin 47 dry cough shortness 47 muscular spasticity 47 lichen planus 47 Hypertrophic 47 ventricular dilation 47 Cardiac arrhythmia 47 Suicidal ideation 47 obstructive lung 47 headaches drowsiness 47 capillary leakage 47 neuropathic nerve 47 autonomic nervous system 47 pneumonia sepsis 47 allergen induced 47 psychosomatic disorders 47 degranulation 47 ventricular fibrillation VF 47 acute hepatic 47 muscular stiffness 47 Multivariate analysis revealed 47 anterior cortex 47 airway constriction 47 reintubation 47 platelet activation 47 vascular dysfunction 47 cerebral ischemic 47 Obstructive Sleep Apnea OSA 47 physiologic parameters 47 postural hypotension 47 hypercoagulability 47 nodal metastasis 47 multi infarct dementia 47 neurologic sequelae 47 arrythmia 47 emphysema COPD 47 profuse watery diarrhea 47 bronchopulmonary dysplasia 47 intima media thickness IMT 47 overactivity 47 AST ALT 47 mucus secretion 47 Glasgow Coma Scale 47 alveolitis 47 neurocognitive deficits 46 paroxysmal supraventricular tachycardia 46 systolic function 46 Circadian rhythm 46 Magnesium deficiency 46 atrial arrhythmias 46 Compulsive hoarding 46 vasovagal syncope 46 inotropes 46 throat irritation headaches 46 neuronal signaling 46 hormone secretion 46 NYHA functional class 46 amyloid plaque formation 46 chest pains shortness 46 AV node 46 kainate 46 tissue necrosis 46 Genetic mutations 46 painful stimuli 46 Seattle Angina Questionnaire 46 paranoia hallucinations 46 interstitial fluid 46 aneurysmal 46 sociodemographic factors 46 cyanosis 46 nonvascular 46 allostatic 46 nasal airway 46 serotonin norepinephrine 46 hyperpyrexia 46 prothrombotic 46 abnormal glucose metabolism 46 urolithiasis 46 lung epithelium 46 barotrauma 46 restlessness irritability 46 wheezing shortness 46 agitation irritability 46 convulsions paralysis 46 Socio demographic 46 cough wheeze 46 psychiatric comorbidity 46 pulmonary vascular 46 interstitium 46 Skin sterol 46 physiologic 46 autonomic arousal 46 Electroencephalography 46 stress echocardiography 46 oxidative metabolism 46 penile erection 46 cardiopulmonary fitness 46 bispectral index BIS 46 species ROS 46 paresis 46 irritability mood swings 46 nausea vomiting headaches 46 gastrointestinal reflux 46 headaches backaches 46 baroreceptor 46 hypoxia ischemia 46 bacterial translocation 46 dystonic 46 counterpulsation 46 Caffeine stimulates 46 fatal anaphylactic 46 diastolic function 46 RNFL 46 frontal parietal 46 brachial 46 dysrhythmia 46 coughing wheezing chest 46 chronic venous insufficiency 46 perceptual biases 46 neuro degenerative disorders 46 cognitive affective 46 biochemical imbalances 46 daytime drowsiness 46 vasoconstrictor 46 lability 46 coagulation abnormalities 46 dissecans 46 AV conduction 46 perinatal asphyxia 46 brain cortex 46 lightheadedness dizziness 46 Vasopressin 46 serum BDNF 46 alveolar epithelial cells 46 corneal thickness 46 hypocalcaemia 46 electrocardiography ECG 46 Opportunistic infections 46 abnormal sensations 46 metabolic abnormality 46 arterial inflammation 46 serum PTH 46 nonspecific symptoms 46 Raynaud phenomenon 46 hemoglobin Hb 46 oxygen homecare 46 bradykinesia 46 Shortness 46 neuronal dysfunction 46 genotype phenotype 46 muscarinic receptors 46 drowsiness irritability 46 locus coeruleus 46 resting ECG 46 palpitations sweating 46 headache nausea fatigue 46 neurobehavioural 46 Digoxin toxicity 46 decrements 46 blurred vision dizziness 46 Pulmonary hypertension 46 wheezing cough 46 multivariable analyzes 46 transcutaneous 46 ejection fractions 46 tiredness irritability 46 brain neurotransmitter 46 adrenocorticotropic hormone 46 nausea headache dizziness 46 beta adrenergic receptors 46 nontraumatic 46 noninvasive ventilation 46 Bispectral Index 46 tinnitus vertigo 46 mechanoreceptors 46 lateral habenula 46 hemolytic 46 Epworth Sleepiness Scale 46 respitory 46 acute asthma exacerbations 46 glomerular 46 hyper arousal 46 cardiopulmonary bypass surgery 46 involuntary tics 46 headache blurred vision 46 acetylcholine neurotransmitter 46 pulse amplitude 46 neuromotor 46 cervical secretions 46 inspiratory muscles 46 oscillatory 46 rhinosinusitis 46 vertigo dizziness 46 hyperarousal symptoms 46 nausea shortness 46 headache vomiting 46 decompensated heart failure 46 obstructive CAD 46 suppurative 46 Electrocardiogram ECG 46 allostatic load 46 vascular constriction 46 valve regurgitation 46 untreated obstructive sleep 46 vasovagal 46 narrowed airways 46 monoamine 46 protein conformation 46 Henoch purpura 46 distensibility 46 progressive neurologic 46 neurocognitive function 46 primary aldosteronism 45 respiratory insufficiency 45 hypoactive 45 biventricular pacing 45 noradrenalin 45 debilitating neurological disease 45 monoamine neurotransmitters 45 system dermatological gastrointestinal 45 cortisol hormone produced 45 dizziness nausea headache 45 demyelinating disorders 45 psychosomatic illnesses 45 neuroactive 45 Chemotherapy induced 45 tarsal tunnel 45 manometry 45 parasitaemia 45 resolves spontaneously 45 mycobacterial infection 45 interobserver 45 Fluid retention 45 nasal symptoms 45 psychopathological symptoms 45 tumor histology 45 haematologic 45 potentiated 45 inducible ischemia 45 interstitial pneumonitis 45 Parkinsonian symptoms 45 electrolyte abnormalities 45 pulmonary emphysema 45 nasal airflow 45 neurological degeneration 45 numbness dizziness 45 extrapyramidal symptoms 45 Tambocor 45 inflamed tissues 45 ischemic cardiac 45 tissue perfusion 45 upper chambers atria 45 generalized anxiety disorders 45 oral thrush 45 myocyte 45 cardiopulmonary 45 Thyroid hormone 45 EtCO2 45 Panton Valentine leukocidin PVL 45 bacterial respiratory infections 45 tricuspid atresia 45 CHADS2 45 mood suicidal ideation 45 convulsive disorders 45 PER2 45 extracellular fluid 45 sequela 45 Difficulty breathing 45 pulmonary fibrosis scarring 45 neuropsychological functioning 45 asthma bronchitis emphysema 45 homeostatic mechanisms 45 Bed sores 45 subclinical atherosclerosis 45 dizziness drowsiness 45 interstitial pneumonia 45 glycaemia 45 neuroinflammatory diseases 45 EEG electroencephalogram 45 coughing shortness 45 bone microarchitecture 45 excitotoxic 45 leukocyte count 45 arterial fibrillation 45 Androgen receptor 45 hyoscyamine 45 hypercholesterolaemia 45 Gastro intestinal 45 lung edema 45 sensory neuron 45 Meniere Disease 45 microvascular endothelial cells 45 allergic inflammation 45 proximal tubule 45 corticotrophin releasing hormone 45 decubitus ulcers 45 venous circulation 45 Secondary endpoints include 45 Breathing exercises 45 enlarged adenoids 45 pulmonary disorders 45 insomnia irritability 45 rebreathing 45 trophic factors 45 Attenuation 45 parkinson disease 45 symptom flare ups 45 registered respiratory therapist 45 hypotension bradycardia 45 sweating nausea 45 Electromyography 45 TT genotype 45 allergic sensitization 45 chemoreceptors 45 HRCT 45 cognitions 45 serum parathyroid hormone 45 chronic airway inflammation 45 bladder bowel 45 hERG channel 45 left ventricular diastolic 45 COPD asthma 45 dopamine signaling 45 histologic subtype 45 methemoglobin SpMet 45 chronic obstructive lung 45 sleep apnea snoring 45 pupil dilation 45 modulatory 45 prognostic indicators 45 basolateral amygdala 45 Mathematical modeling 45 natriuretic peptides 45 embolic stroke 45 intravascular fluid 45 immuno deficiency 45 peroneal 45 normothermic 45 fatigue nausea vomiting 45 glial tumors 45 respiration 45 emphysema chronic bronchitis 45 hyperoxia 45 painful muscle spasms 45 neurocognitive functioning 45 hypocretin neurons 45 posttraumatic 45 diabetes mellitus hypertension 45 evoked potentials 45 protozoal 45 Secondhand smoke exposure 45 Pericarditis 45 cerebral spinal 45 monoclonal gammopathy 45 nonhealing wounds 45 asthma exacerbation 45 drowsiness nausea 45 G6PD deficiency 45 hypersalivation 45 microsleep 45 hemorrhagic pancreatitis 45 tracer uptake 45 progressive neurodegenerative 45 headache nausea dizziness 45 hypoxic brain 45 hepatic renal 45 asthma allergic rhinitis 45 nausea vomiting headache 45 stroke hypertension palpitations 45 rheumatoid factor 45 psychiatric comorbidities 45 Chlamydia trachomatis infection 45 syncope 45 psychiatry neurology 45 diabetic kidney 45 angina chest 45 hepatitis B infection 45 arteriolar 45 familial clustering 45 acute febrile 45 convergent validity 45 hyperintensities 45 daytime somnolence 45 adrenal hormones 45 JAK STAT pathway 45 thrombosis blood clots 45 pulmonary thromboembolism 45 morphologic characteristics 45 genetic locus 45 fat malabsorption 45 bleedings 45 NIH CPSI 45 Migraine headache 45 thrombophlebitis 45 respirations 45 basophils 45 Heritability 45 depolarization 45 sleep apneas 45 physiological responses 45 photic 45 Known hypersensitivity 45 cortisol concentrations 45 tamponade 45 afferents 45 polydipsia 44 syndromal 44 irritability restlessness 44 palpitation 44 menstrual irregularity 44 weakly correlated 44 bronchial airways 44 neuropsychological deficits 44 inhibitory transmitter 44 pulse respiration 44 blindness paralysis 44 Bronchiolitis 44 H#N# virus replicates 44 Rotavirus infections 44 extracellular calcium 44 dizziness nausea vomiting 44 Muscle spasms 44 airway epithelium 44 either acutely decompensated 44 distractibility impulsivity 44 arteries dilate 44 rACC 44 claudication 44 cystoscopic 44 uncontrollable shaking 44 Th2 immune 44 afterload 44 coronary microvascular 44 overactivation 44 indicates cardio circulatory 44 Sleep disordered breathing 44 involuntary jerking 44 ECG waveforms 44 chronic bronchitis asthma 44 cervical spinal cord 44 fluid shear 44 airway hyper 44 adrenal cortex 44 cardiac insufficiency 44 apo E 44 cerebral vascular disease 44 countertransference 44 diabetes hypertension hyperlipidemia 44 diurnal variation 44 DVT PE 44 bladder contractions 44 infective endocarditis 44 ADCS CGIC 44 actin dynamics 44 Main Outcome Measure 44 Microstream R capnography 44 striatal 44 idiopathic Parkinson disease 44 Nausea vomiting 44 abdominal pain vomiting diarrhea 44 FFR measurements 44 SpO 2 44 serum homocysteine 44 Mitral valve