Whole&Heart&Experiment&&Write&this&up&as&a&standard&short&lab&rep ort&(Intro ,&me tho ds,&resu lts,&and &con clu sions )&using &the&guidelines&provided&by&Dr.&Sanguinetti.&&Rationale:&Premature&ventricular&contractions&(PVCs)&are&difficult&to&reproduce&in&the&experimental&setting.&&In&order&to&study&PVCs,&one&nee ds&a&re pro du cible&m o de l.&It&is&known &tha t&digoxin&increase s &th e &incidenc e &of &PVCs&but&th e &timing&of&su ch &p h e n o m e n o n &ap p e a r&ra nd o m.&&In&this&lab o r at o ry ,&yo u &will&take&op tic a l&m a p s &o f&L angendo rf f&p e rfu s ed &g u in e a &p ig &h ea rt s&with&diI4IANEPPS&&in&the&abs e n ce &a n d &presenc e &o f&0 .7 5µM&digoxin.&&Specific&Objectives:&1. Quantify&the&time&to&the&first&PVC&and&QRS&duration&of&the&first&PVC&after&variable&pacing&cycle&lengths. &2. Determine&the®ion&of&the&heart&where&the&first&beat&originates&&&Protocol'(Group'1)'1. The&heart&will&be&hanging&and&the&cameras&will&be&setup&for&your&experiment&when&you&enter.&&2. Perfuse&diI4IANEPPS&into&the&heart.&3. After&the&dye&is&perfused&and&the&heart&has&recovered&for&a&few&minutes,&&begin&the&protocol&on&the&attached &shee t.&a. You&will&need&one&person&to&take&the&recording&(sitting&at&the&computer)&b. One&person&to&change&the&pacing&rate&(Stimulator)&c. One&person&to&measure&time&to&first&beat&and&QRS&interval&from&the&oscilloscope.&d. You&may&choose&to&rotate&who&does&what&&Protocol'(Group'2)'1. If&the&first&g ro u p &h a s &n o t&fin is h e d &th e &c o n tro l&r e co r d in gs ,&gr o u p &2 &will&finish&th o se &re c o rd in g s&using&the&same&distribution&of&labor&as&outlined&above&in&point&3&aId&2. Once&all&control&recordings&are&completed,&group&2&will&perfuse&0.75&µM&digoxin&into&the&heart&for&20&minute s.&3. If&time&pe r m it s,&g ro u p &2 &will&contin u e &to &fill&o u t &th e &sh e e t.&&Protocol'(Group'3)'1. If&the&2nd&gro u p &h a s &n o t &fin is h e d &th e &digoxin&record ings,&grou p &2 &will&finish&th o s e &re cordings&using&the&same&distribution&of&labor&as&outlined&in&group&1,&points&3&aId&&Tasks:'Whole'Heart'Lab.'At&the&end&of&the&entire&experiment,&everyone&will&be&given&the&same©&of&the&data&which&has&pacing&rate,&time&to&first&beat,&an d&Q RS &wid th.&&Results'1:&Here&is&the&data&for&past&control&experiments&(time&to&first&beat).&Please&add &you r&data &as&the &5th&experiment&&BCL&Exp&1&Exp&2&Exp&3&Exp&4&350&790&600&600&720&300&820&620&630&850&280&2680&660&680&950&260&2840&680&700&1010&250&3720&720&730&1130&240&3720&740&750&1160&230&4880&800&810&&220&5160&820&970&&200&5440&900&2360&&180&&&3060&&160&&&&&150&&&&&&&Here&is&the&data&for&past&0.75µM&digoxin&expe riments&(t ime&to&first&b e a t ).&P le a s e &a d d &y o u r&d a t a &a s&the&4th&experiment.&&BCL&11031001&11031002&110910&350&620&540&520&300&640&560&530&280&680&460&550&260&500&480&440&250&400&380&520&240&360&360&320&230&280&310&320&220&240&270&240&200&240&250&240&180&220&&280&160&220&&280&150&240&&260&140&210&&260&130&250&&230&&Plot&the&mean&and&standard&error&for&these&two&graphs&(Time&to&1st&beat&vs .&B a s ic&C y c le &Le n g t h &[B C L ]) .&&Results'2:&Plot&you r &d a ta &f o r&QRS&as&a &fu n c tio n&of&BCL .&T h e re &is &n o &p re v io u s &d a ta &on&this&Results'3:&You&w ill&re c e ive &4 &f ile s,&which&ar e &m ovies&of&th e &r e co r d in g s&y o u ’v e &made&fo r&s p e c ific &co n ditions&and&pacing&rates.&Determine&which&part&of&the&heart&the&first&spontaneous&beat&originated.&&Discussion/Conclusion:'Discuss&whether&your&data&fit&previous&trends&or&significantly&deviated.&Use&appropriate&statistical&analysis&to&determine&whether&there&are&any&changes&in&time&to&1st&beat&as &a &re s u lt&of&the&dig o x in .&Discuss&which&pacing&rates&produce&significantly&different&results.&&Research&and&discuss&whether&the&time&to&first&beat&results&for&all&experiments&is&consistent&with&what&is&in&the&litera t ur e,&a n d &w h a t&th e &mechanism&is.&&With&digoxin,&discuss&a&mechanism&why&it&may&have&modified&time&to&first&beat&if&your&statistics&support&that&finding.&&Last,&consider&what&QRS&duration&means&and&explain&why&QRS&duration&may&have&been&different&as&a&result&of&pacing&rate &and &dig o xin
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